Kids pay attention longest to activities they chose themselves.
Not graded
Study not named in brief (§7)
Not graded in brief; stated as a finding in §7
Who was studied: Three-year-olds, in different teaching setups.
What they found: Activities the child picked held attention the longest. Activities an adult picked came second. Activities an adult simply presented came last. We have to be straight with you here. We could not find the published study behind this one.
What it means for you: The child leads. That is the default shape of every pack. But we hold this one loosely until the study turns up.
An old rule of thumb ties focus time to age. Treat it as a guess.
Folk rule
Folk rule, as recorded in brief (§7); no study named
Folk rule, recorded at that strength (§7)
Who was studied: No study. This is a rule passed around by teachers and parents.
What they found: The rule says a child can focus on a task he did not choose for about two to three minutes per year of age. That means roughly 15 to 20 minutes at age 7. Chosen tasks kids care about run far longer. No solid study backs the numbers.
What it means for you: We use the range only to size a session. We never promise your child will focus for a set number of minutes.
Kids say good play means feelings, freedom, and friends. Not lessons.
Not graded
Aarhus University (2026), Frontiers in Psychology
Not graded in brief (§5, item 8)
Who was studied: 104 children told their play stories. Then hundreds more children rated statements about play.
What they found: Kids defined good play by imagination and wild, energetic play. Silliness and bending the rules counted too. So did playing with others. Learning goals and good behavior did not define it.
What it means for you: Missions are built to feel like play to the child. Silliness and a little rule bending are allowed on purpose. We never pitch a mission to a child as a lesson.
Pretend play warms up slowly. It peaks 10 to 15 minutes in.
Not graded
SWPS University study, as cited in brief (§5, item 8)
Not graded in brief
Who was studied: The brief does not name the children or their ages.
What they found: Engagement in pretend play climbed after play began. It peaked about 10 to 15 minutes in. It did not peak at the start.
What it means for you: Packs open gently and ask for more later. We never judge a mission by its first two minutes.
Kids with more free, unstructured time run their own minds better.
Moderate
Barker et al. (2014), Frontiers in Psychology
Moderate (§5, item 7)
Who was studied: Six-year-olds. Researchers tracked how their weeks were spent.
What they found: Children whose weeks held more loosely structured time did better at directing their own thinking. They set their own goals and kept at them. The link showed up in how the week was filled, not in lessons.
What it means for you: A pack lights the spark and then gets out of the way. We do not fill every minute with directions.
Boredom might feed creativity later. The proof is in adults only.
Moderate
Mann & Cadman (2014)
Moderate heading in brief (§5, item 7) with the child claim downgraded to suggestive
Who was studied: Adults. No children took part.
What they found: Adults who did a boring task first came up with more creative ideas after. Nobody has shown this in children. For kids it is a hint and nothing more.
What it means for you: We leave some open space in a pack and do not panic about it. We never claim downtime in a pack makes your child more creative.
Focus grows fast from 5 to 9. Then it levels off.
Strong
Betts, McKay, Maruff & Anderson (2006), Child Neuropsychology 12(3), 205 to 221.
Strong: direct age range, standardized battery, clear trajectory
Who was studied: 57 children, ages 5 to 12, on standard attention tests.
What they found: Focus jumped from age 5 to 6 and again to 8 to 9. Then it flattened out toward age 10 to 12. Tasks with a heavy mental load hurt focus at every age.
What it means for you: A 10-year-old can hold a mission longer than a 5-year-old. So the youngest kids get shorter and simpler missions. One ladder for all ages would be wrong.
Splitting attention between two things at once is the real bottleneck.
Strong
Talalay (2024), Psychology in the Schools 61(6), 2223 to 2239.
Strong: large N, in-range, effect pattern replicated across measures
Who was studied: 199 children, ages 6 to 12.
What they found: Picking out one thing from a busy scene improved bit by bit with age. Handling two streams of information at once improved a lot between 6 and 12. Trying to track two things at once badly hurt performance. The youngest children suffered most.
What it means for you: One mission thread at a time. We never ask a young child to follow two things at once.
Deep focus comes when the challenge is high and the skill matches it.
Moderate
Rathunde & Csikszentmihalyi (2005), American Journal of Education 111(3), 341 to 371.
Moderate: strong ESM design, but age-out-of-range and school-context confound
Who was studied: About 290 middle school students. They are older than our kids. Researchers paged them at random moments and asked what they felt.
What they found: Montessori students reported more flow and undivided interest in schoolwork than students in regular schools. Flow was strongest when challenge and skill were both high and in balance. Feeling the work mattered and having some control helped too. There was no gap in free time activities.
What it means for you: Missions let the child pick the difficulty and set the pace. But this study used older kids in schools. We treat it as a direction, not proof for age 7.
Teens engage most when work is hard, matched to skill, and theirs to steer.
Thin
Shernoff, Csikszentmihalyi, Schneider & Steele Shernoff (2003), School Psychology Quarterly 18, 158 to 176.
Thin (for this product): classic flow-ESM pattern but older sample, no 5 to 10 replication in hand
Who was studied: 526 US high school students. Well above our age band.
What they found: Engagement peaked when challenge and skill were both high and balanced. Work that felt relevant raised it. So did student control. Kids engaged more in solo and group work than in lectures, videos, or exams.
What it means for you: Balance, relevance, and control point the same way as the study above. Nobody has pinned down the exact balance point for ages 5 to 10. We will not pretend otherwise.
Kids who rarely read still get lost in a good story by age 10.
Moderate
Prezioso & Harris (2025), Psychology of Aesthetics, Creativity, and the Arts 19(4), 747 to 759.
Moderate: in-range, but self-report and small N
Who was studied: 66 children, ages 9 to 11.
What they found: Children described getting absorbed in stories through focus, feelings, and pictures in the mind. At age 9, keen readers absorbed more than rare readers. By 10 to 11 the gap was gone. Rare readers absorbed just as much.
What it means for you: Story missions are not just for bookish kids. A child does not need to call himself a reader to get pulled in.
Thrill-seeking kids skip reading. A story that grabs them fixes that.
Moderate
Jensen, Imboden & Ivic (2011), Scientific Studies of Reading 15(6), 541 to 558.
Moderate: survey, but in-range with a clean moderation pattern
Who was studied: 120 children in grades 4 and 5.
What they found: Children who seek strong sensations read less for fun. Boredom sat in the middle of that link. But when a story truly pulled a thrill seeker in, he read like anyone else. Science fiction and fantasy pulled hardest.
What it means for you: For a thrill-seeking child, missions start fast and drop him straight into the world. Quiet and gentle is the wrong door for him.
A story that grips kids makes them stick longer with hard thinking after.
Moderate
Dore, Smith & Lillard (2017), Child Development Research, Article ID 6838079.
Moderate: experimental, in-range, but narrative-engagement measure is brief
Who was studied: Two studies. 96 children ages 7 and 10, then 104 more children.
What they found: Children who got pulled into a story about a professor spent more time on a hard puzzle toy after it. Telling kids to step into the character's shoes pulled them in deeper. A boring lead-in did not do this.
What it means for you: A short story hook can open a thinking mission. The hook has to grip, though. Just reading any story first is not enough.
A story that ends on a cliffhanger brings kids back. One-off episodes fade.
Moderate
Lu, Green, Sousa, Hwang, Lee, Thompson & Baranowski, Communication Research 52(5), 600 to 625 (online 2023).
Moderate: RCT, in-range, but small N and a video-game context
Who was studied: 44 children, ages 8 to 12, in a randomized study with repeated visits.
What they found: Children who got a serial story with cliffhangers moved more and played longer across visits. Children who got finished one-off episodes played less and less. Oddly, the two groups said they felt equally pulled into the story.
What it means for you: Missions link into arcs with a reason to return tomorrow. We watch what kids do, not just what they say was fun. And no study has mapped the perfect difficulty climb for paper games. We say that plainly.
Only about 1 in 10 kids collects things. It peaks near age 10.
Moderate
Lehman & Witty (1927), Psychological Review 34(1), 48 to 56.
Moderate: historical survey, but the "no spike" and "peak at 10" pattern is the only age-graded collecting data in hand
Who was studied: A large group of children, surveyed long ago in 1927.
What they found: Collecting did not suddenly switch on at any age. Only about 10 percent of children were actively collecting. The effort they put into it peaked at age 10. Older children lost interest.
What it means for you: Collecting can be one fun option near ages 9 and 10. It is not the engine of the product. Most kids are not collectors.
Kids come back to unfinished tasks. That part is solid. The memory claim is not.
Thin
Zeigarnik (1927), Psychologische Forschung 9, 1 to 85 (with Ovsiankina 1928).
Thin: foundational and famous, but 1927 methods and secondary sourcing
Who was studied: 138 children in the original 1927 experiments.
What they found: More than 80 percent of children went back to a task left unfinished. Only 6 percent went back to a finished one. The old claim said unfinished tasks are also remembered better. A 2025 review of the whole record cut that memory claim down. The coming back part held up. About two times in three, people return.
What it means for you: Missions can pause in the middle and wait. An unfinished mission on the table is an invitation. We never claim leaving one open makes your child remember it better.
People push harder toward whichever end of a goal looks smaller.
Thin
Koo & Fishbach (2012), Journal of Consumer Research 39 (Oct 2012), "The Small-Area Hypothesis."
Thin (for this product): adult consumer studies, mechanism plausible but untested in 5 to 10s
Who was studied: Adults. No children took part.
What they found: Early in a goal, people work harder when shown the progress already made. It looks small and fast. Near the end, they work harder when shown the little bit left. Motivation followed whichever side was smaller.
What it means for you: Progress on a pack flips its message as a set nears the end. First it counts what is done. Then it counts what is left. This comes from adults, so we use it as a light touch.
A token game with a dash of luck got kids doing more math, and getting more right.
Moderate
Eckert, Scherenberg & Klinke (2023), Frontiers in Psychology 14:1077406.
Moderate: in-range and analogue (non-digital), but small pilot, quasi-experimental
Who was studied: 39 elementary school children, average age about 8 and a half. The game ran for two weeks.
What they found: Children playing the token game finished more math exercises than before. They also solved more correctly than the group without the game. The surprise in the rewards seems to be what pulled them.
What it means for you: A small luck element can live inside a skill game. Pure luck games are not the engine. And two weeks is all this study ran, so we claim nothing long term.
Game elements beat none. Surprise rewards beat set rewards by nothing.
Moderate
Ghanbari, Mahdavinasab & Mohammadhasani (2024), Interdisciplinary Journal of Virtual Learning in Medical Sciences 15(2), 180 to 191.
Moderate: quasi-experimental, in-range, and the null is the point
Who was studied: 84 sixth graders, split into surprise reward, set reward, and plain online learning groups.
What they found: Both game groups learned more than the plain group. The surprise reward group scored a little higher than the set reward group. That gap was too small to count as real.
What it means for you: Steady and predictable rewards are fine. Surprise is flavor, not a proven booster. We will not tell you otherwise.
Loot boxes work like gambling. They stay out. Full stop.
Moderate
Drummond & Sauer (2018), Nature Human Behaviour (loot-box/gambling analysis).
Moderate: structural analysis, widely cited, but not an RCT in children
Who was studied: No child sample. The researchers analyzed how loot boxes are built and how they act on the mind.
What they found: Loot boxes meet the tests for gambling in both build and effect. Children who are exposed to gambling early face higher risk of gambling problems later.
What it means for you: This entry is a guardrail. No chance boxes appear in anything we make, paid or free. "It is not real gambling" is not an argument we accept.
Chance games made math feel safer. They did not build confidence.
Thin
Nisbet & Williams (2009), Australian Mathematics Teacher (chance games in maths).
Thin: small, short, borderline age, no effect sizes reported
Who was studied: Two Year 7 classes, ages about 11 to 12. Just above our band. They played six chance games over two weeks.
What they found: The children enjoyed math more and wanted to do more of it. They felt less anxious about chance and saw more use in the subject. Their confidence did not rise in any way that counted.
What it means for you: A short chance game can be a gentle first step into number play. We never promise it makes a child confident.
How funny a child is depends heavily on who he plays with.
Strong
Paine, Hashmi, Fink, Mitchell & Howe (2025), Communications Psychology 3:76.
Strong: in-range, observational, partner effects modelled properly
Who was studied: 130 UK children, ages 5 to 7. Researchers coded humor in their play.
What they found: The play partner alone explained 42.8 percent of the differences in how much humor a child produced. The same child could be hilarious with one partner and flat with another.
What it means for you: Silly missions work best in pairs, where kids bounce off each other. A joke script printed on a card cannot carry humor alone.
Babies who laughed copied a silly demo more. That is all this one can say.
Thin
Esseily, Rat-Fischer, Somogyi, O'Regan & Fagard (2016), Cognition & Emotion 30(4), 817 to 825. (DOI confirmed on the article itself; the university repository URL recorded earlier was truncated at the source and is replaced by the DOI)
Thin (for this product): mechanism suggestion only, far below age range
Who was studied: 53 babies, 18 months old. Far below our age band.
What they found: Babies who laughed at a funny tool demo copied the action far more often. About 94 percent of the laughers used the tool right, against 25 percent in the plain demo. The researchers warn that happy temperament, not humor itself, may explain it.
What it means for you: A silly demo before a fiddly task is a cheap thing to try. This study cannot prove humor helps learning at ages 5 to 10.
Team games versus rival games changed no behavior. Kids liked team games more.
Moderate
Eriksson, Kenward, Poom & Stenberg (2021), Scandinavian Journal of Psychology 62, 355ff.
Moderate: RCT-ish design, but ages 4 to 6 and one game set
Who was studied: 65 children, ages 4 to 6, playing board games in groups of four over six weeks.
What they found: Cooperative and competitive games produced the same kind and unkind behavior after play. Neither made children nicer or nastier. The children enjoyed the cooperative games more.
What it means for you: Either style of rules is allowed. We lean cooperative because kids enjoy it more. We never claim rival games harm children or team games make them kind.
Hearing the same story again and again is how toddlers learned the words.
Moderate
Horst, Parsons & Bryan (2011), Frontiers in Psychology 2:17. (Same study as BLD-09, filed there for word learning; filed here for repetition and re-play value.)
Moderate: clean exposure control, but N=16 and age 3
Who was studied: 16 children, all age 3. Below our band.
What they found: One group heard the same stories three times in a week. The other group heard different stories with the same new words in them. Only the same-story group learned the words. They still knew them a week later.
What it means for you: A favorite mission is built to be replayed word for word. Same frame each time frees the child's mind to notice new detail. New is not always better.
"You are so smart" backfires. "You kept trying" works.
Strong
Mueller & Dweck (1998), Journal of Personality and Social Psychology 75(1), 33 to 52 (PMID 9686450).
Strong (finding): replicated pattern, in-range; citation link tier ⚠️ (canonical page not opened in this harvest)
Who was studied: Six studies. The first had 128 fifth graders, ages 10 to 12.
What they found: Children praised for being smart picked easier problems afterward. After a failure they gave up sooner, enjoyed it less, and blamed low ability. Some even lied about their scores. Children praised for effort picked harder problems and hunted for better strategies.
What it means for you: Cards praise effort and strategy in plain words. "You kept trying different ways." Never "you are so smart."
A promised prize cut later play in half. A surprise prize did not.
Moderate
Lepper, Greene & Nisbett (1973), Journal of Personality and Social Psychology 28(1), 129 to 137.
Moderate: classic, but old, small, and exact N unconfirmed
Who was studied: Preschoolers who already loved drawing.
What they found: Children promised a "Good Player Award" for drawing later spent about half as much free time drawing. Children who got the same award as a surprise drew as much as ever. Only the expected reward did the damage.
What it means for you: Bonuses arrive as surprises. No card ever says "finish this and earn that."
Across 128 experiments, prizes undercut free choice. Praise lifted it.
Strong
Deci, Koestner & Ryan (1999), Psychological Bulletin 125(6), 627 to 668.
Strong: large meta-analysis, child-relevant pattern, with a noted counter-meta-analysis
Who was studied: A review of 128 experiments. The prize effect hit children harder than college students.
What they found: Every kind of expected prize lowered children's later interest when the choice was theirs. The drop was real and steady. Warm and specific feedback raised it. One rival review reached a softer verdict, and that dispute is real. We do not hide it.
What it means for you: Feedback on cards talks about the work itself. There is no prize ladder at the center of a pack.
Kids engage most with adults and peers together. Not peers alone.
Thin
Shernoff & Vandell (2007), Journal of Youth and Adolescence 36, 891 to 903.
Thin (for this product): above-range ESM, but the adult+peer pattern is the only duration-relevant social finding in hand
Who was studied: 165 middle school students. Above our band. Researchers sampled their moments over time.
What they found: Engagement ran highest in sports and arts activities. Activities with both adults and peers present beat activities with peers only.
What it means for you: Some missions want a grown-up nearby. Some want a partner. We do not assume a solo mission holds a child the same way. This study used older kids, so we hold it at hint strength.
A 10 minute movement break reset focus. Five and 20 minutes did not.
Moderate
Howie, Beets & Pate (2014), Mental Health and Physical Activity 7(2), 65 to 71.
Moderate: in-range, within-subjects, but dose pattern is non-monotonic and needs replication
Who was studied: 96 children in grades 4 and 5. Each child tried every break length.
What they found: After a 10 minute exercise break, children stayed on task 87.6 percent of the time. Sitting still gave 77.1 percent. Breaks of 5 and 20 minutes showed no clear gain.
What it means for you: A movement card of about 10 minutes can sit mid session as a reset. Length matters here. Any old break will not do.
Movement breaks lifted math scores. They did not lift thinking control tasks.
Moderate
Howie, Schatz & Pate (2015), Research Quarterly for Exercise and Sport 86(3), 217 to 224.
Moderate: same sample as HOLD-30, so not independent replication
Who was studied: The same 96 children as the study above, ages 9 to 12. Same group, so this is not a second proof.
What they found: Math scores rose after 10 and 20 minute exercise breaks. Scores on self control and planning tasks did not move at all.
What it means for you: A movement reset can come right before a counting or math mission. We never claim breaks sharpen self control. The test looked and found nothing.
Three short active breaks a day raised movement and focus over 12 weeks.
Moderate
Li, Liu & Zhao (2026), Frontiers in Public Health 14:1905069.
Moderate: very large RCT, but single site and the 5-min dose conflicts with HOLD-30's null for 5 minutes (different outcome/dose schedule)
Who was studied: 1,248 children in grades 1 to 6, in a large randomized study over 12 weeks.
What they found: Children with three 5 minute active breaks a day moved much more and sat much less. Their focus scores rose sharply. Younger children and weak focus children gained most. Note the clash. The study above found 5 minute breaks did nothing. The setup differed, and we do not pretend the two agree.
What it means for you: Short movement breaks sprinkled through a day are a safe bet. We just cannot tell you the one true break length. Nobody can yet.
Bored young kids mostly go find a person or a toy. That is how they cope, full stop.
Moderate
Anderson & Perone (2024), Journal of Experimental Child Psychology 243, 105919.
Moderate: in-range-adjacent, but coping is not creativity
Who was studied: 130 children, ages 4 to 6.
What they found: Boredom worked in these young children much as it does in adults. When bored, most children asked a parent to play or picked up toys. The researchers expected certain boredom types to match certain coping moves. That link came up empty.
What it means for you: A pack can treat boredom as a cue card. "You are bored. Pick a toy or find a person." This study shows coping, not creativity. We claim nothing more from it.
Kids left to beat boredom themselves leaned in harder. Early word only.
Thin
Perone, Vaughan, Anderson & Weybright (2026), Infant and Child Development 35(4), e70119.
Thin: secondary sourcing only; treat as a lead, not an entry-grade finding
Who was studied: Children, but we could not confirm the exact number or ages. This entry rests on a summary by others, not the paper itself.
What they found: Children whose parents let them sort out boredom on their own showed brain activity tied to moving toward a task. They showed it even on a boring task.
What it means for you: At most, this is an idea to test. Let a child sit with boredom a short while before a mission lands. We make no brain claims from this one.
Loose parts are fun. Proof they build skills does not exist.
Strong
Gibson, Cornell & Gill (2017), School Mental Health 9(4), 295 to 309.
Strong (as a null): systematic review with explicit quality judgement
Who was studied: A review of every solid study on loose parts play. Only 5 studies passed the bar. All used primary school children.
What they found: No study showed gains in friendship, social skill, or quality of life. No study even measured thinking or school outcomes. Enjoyment and self esteem showed small positive signs. The famous loose parts theory from 1972 is a theory. It is not evidence.
What it means for you: Open ended stuff earns its place because kids enjoy it and lead it themselves. We never say loose parts improve social skills or learning. The review says that proof is not there.
A yard full of loose stuff did not lengthen play. Not one bit that counted.
Moderate
Bundy et al., Sydney Playground Project (cluster RCT; protocol Bundy et al. 2011, BMC Public Health 11:680), as tabulated in Gibson et al. (2017).
Moderate: cluster RCT, in-range, null on the exact outcome this product cares about (engagement time)
Who was studied: 226 children, ages 5 to 7, in 12 Australian primary schools. Their playgrounds got tyres, crates, and hay bales for 13 weeks.
What they found: Time spent engaged in play did not change in any way that counted. The number of playmates did not change either. Teachers also got talks on letting kids take risks.
What it means for you: Loose materials are one ingredient. They are not a promise of longer play. This study tested the exact thing parents hope for, and it came up empty.
Working together beat rivalry and solo work on results. Rivalry and solo tied.
Strong
Johnson, Maruyama, Johnson, Nelson & Skon (1981), Psychological Bulletin 89(1), 47 to 62.
Strong for the achievement ordering (the anchor meta-analysis of the goal-structure literature); indirect for this product, because the outcome is school task achievement, not holding time in play
Who was studied: A review of 122 North American studies across school ages. The outcomes were school results and output, not play time.
What they found: Children working toward a shared goal did far better than children competing head to head. They also beat children working alone. Teams competing against other teams did well too. Head to head rivalry and working alone came out the same.
What it means for you: Partner and group missions default to a shared goal. Teams against the game is the allowed form of rivalry. This is school results evidence, so we borrow the shape, not a play promise.
Every named teamwork method beat rivalry and solo work in class.
Strong
Johnson, Johnson & Stanne (2000), Cooperative Learning Methods: A Meta-Analysis, University of Minnesota monograph.
Strong as a synthesis of named methods; achievement outcome in classroom settings, so indirect for play engagement
Who was studied: A review of 164 school studies, from preschool to college. Eight named teamwork methods were tested.
What they found: All eight methods beat competitive and solo setups on school results. One method, Learning Together, won by the widest margin. Rivalry and solo work were again a near tie.
What it means for you: Group missions use real structure. Roles. A team goal. A team contest now and then. Just putting kids in a group is not teamwork, and this review only tested the structured kind.
Head to head rivalry made kids ask "was I smart?" Solo goals made them ask "how do I do this?"
Moderate
Ames (1984), Journal of Educational Psychology 76(3), 478 to 487.
Moderate: a single in-band experiment with a small N and one task type, but the manipulation is the exact variable and the mechanism (attributions) is measured directly
Who was studied: 88 children in grades 5 and 6, working on a new puzzle task.
What they found: Children in the rivalry setup blamed or credited their ability. Children set against their own mark credited effort instead. They talked themselves through the task and watched their own progress. How a child explained the result also drove how he felt about it.
What it means for you: Hard missions default to "beat your own last mark." That frame protects the will to keep trying. We keep head to head framing away from a child who just failed.
Team play gave the warmest feelings about math games. Scores did not move.
Moderate
Ke (2006), Proceedings of the 7th International Conference on Learning Sciences, pages 313 to 320.
Moderate: in-band, real games, four weeks; but one game set, class-level assignment, and a self-reported attitude outcome
Who was studied: 124 fifth graders in eight classes. They played math games twice a week for four weeks, as teams, as rivals, or alone.
What they found: The team setup produced the most positive feelings about the activity. Test scores did not differ across the three setups. Family income changed how the setups landed, so one size did not fit all.
What it means for you: Team framing helps when the problem is how a child feels about starting. That is the stand-off moment, and it is a feelings problem. We never promise team play raises scores. In this study it did not.
A partner in either role raised interest. Teammates most wanted to play again.
Thin
Plass, O'Keefe, Homer, Case, Hayward, Stein & Perlin (2013), Journal of Educational Psychology 105(4), 1050 to 1066.
Thin for this product: a clean experiment and the only head-to-head here on enjoyment and replay intention, but above band, small N, and a single screen game
Who was studied: 58 middle school students. Above our age band. They played a math video game alone, against a rival, or with a teammate.
What they found: Rivalry raised in-game learning over solo play. Both rivalry and teamwork raised interest and enjoyment. Playing as a team lowered scores during the session itself. But teammates most wanted to play again and to recommend the game. Skill outside the game rose for everyone and did not differ by setup.
What it means for you: A partner, rival or teammate, is a real interest lever. We claim that at hint strength for our ages, since these were older kids and one screen game. The classroom reviews above point the other way on rivalry and results, and we follow them for results.
Team games made older kids feel closer and more able. "More fun" barely showed.
Thin
Engels & Freund (2020), PLoS ONE 15(12), e0243608.
Thin for this product: above band, small effects, and the headline enjoyment effect did not reach significance; entered because it is a rare direct cooperative versus competitive games test with enjoyment as the outcome
Who was studied: 285 students, ages 10 to 16, in German gym classes. Only the youngest edge touches our band.
What they found: Cooperative games raised feelings of closeness and of being able. The enjoyment edge was small and did not quite reach the bar for counting as proven. The good feelings about closeness and ability carried part of that small edge.
What it means for you: Team framing in movement missions is a fair bet for closeness and confidence. We hold it at hint strength. We never print "team games are more fun" as a flat fact.
For young teens, teamwork linked to both better results and better friendships.
Moderate
Roseth, Johnson & Johnson (2008), Psychological Bulletin 134(2), 223 to 246.
Moderate as a synthesis; Thin for this product by age. It is the only goal-structure synthesis that measures peer relationships as an outcome, and its sample sits entirely above the band
Who was studied: A review of 148 studies with over 17,000 early teens, ages 12 to 15, in 11 countries. Entirely above our band.
What they found: Teamwork setups came with higher achievement and warmer peer relationships than rivalry or solo setups. Under teamwork the two fed each other. Doing well and getting along rose together.
What it means for you: Partner missions are more than task shapes. They build the relationship too. That claim is borrowed from teen data, and we label it as such. The in-band anchors are the four studies above this one.
Choice makes kids try harder. Two to four choices in a row work best.
Strong
Patall, Cooper & Robinson (2008), Psychological Bulletin 134(2), 270 to 300.
Strong (for the choice effect in children): a 41-study meta-analysis in the field's top review journal, with the child advantage tested rather than assumed; most underlying child studies are short lab or classroom tasks
Who was studied: A review of 41 experiments with children and adults. The researchers tested age head on.
What they found: Choice raised motivation, effort, results, and feeling able. The lift was bigger for children than for adults. Small side choices counted as much as big ones. Two to four choices in a row worked best. A reward handed over after the choice weakened the effect.
What it means for you: Missions hold small real choices. Which object. Which order. Which door. Even looks-only choices are worth building. We never pair a choice with a promised prize, and we never stack more than four choices in a row.
"You will be tested on this" killed interest. The same lesson without pressure did not.
Moderate
Grolnick & Ryan (1987), Journal of Personality and Social Psychology 52(5), 890 to 898.
Moderate: a single in-band experiment at the top of the band, small N, but a direct manipulation of framing with a follow-up, and consistent with HOLD-46 at the band's lower end
Who was studied: 91 fifth graders, about ages 10 to 11.
What they found: Both taught groups memorized more than the left-alone group. The pressure group felt squeezed and lost interest. Their memorized facts also faded faster over eight days. The no-pressure taught group learned the ideas just as well and kept their interest.
What it means for you: No card carries test, grade, or checking language. Structure is fine. Pressure is the poison, and this study pinned it down.
The words of a rule do the damage. The rule itself does not.
Moderate
Koestner, Ryan, Bernieri & Holt (1984), Journal of Personality 52(3), 233 to 248.
Moderate: one small experiment, but in-band, a direct wording manipulation, and the cleanest available evidence that the wording of a rule, not the rule itself, does the damage
Who was studied: 44 children in grades 1 and 2, about ages 6 to 8, doing a painting activity.
What they found: Limits stated as orders ("you have to," "be a good boy or girl") cut motivation, enjoyment, and creativity. The paintings scored worse too. The same limits stated as plain facts about the materials did no harm at all. They matched having no limits.
What it means for you: Pack rules are written as facts. "The small sheet is yours. The big sheet stays clean." Never as obedience demands. Every printed instruction gets checked for pressure wording.
Who picks matters. Some kids light up when a trusted person picks for them.
Moderate
Iyengar & Lepper (1999), Journal of Personality and Social Psychology 76(3), 349 to 366.
Moderate: two experiments, in-band, yoked designs so the activities themselves were identical across conditions; the moderator is cultural background in one US metropolitan sample, so the size of the effect in any given family is unknown
Who was studied: Two studies. 105 children in grades 3 to 5, then 88 fifth graders. Anglo American and Asian American families.
What they found: Anglo American children did best and stayed longest when they picked themselves. They did worst when others picked. Asian American children showed the mirror image. They did best when their mother or their classmates had picked. The activities were identical either way. Only the picker changed.
What it means for you: "Peg picked this for you" stands beside "you pick" as an equal door into a pack. We ask families who should choose. We never claim picking it yourself is the only route that works.
For kids who resist, a choice of task or order cut problem behavior.
Moderate
Shogren, Faggella-Luby, Bae & Wehmeyer (2004), Journal of Positive Behavior Interventions 6(4), 228 to 237.
Moderate: a real meta-analysis of the closest population to the reactant use case (children who can do the task but will not), but single-case designs, a weak effect metric, mixed ages, and disability samples in mostly school settings
Who was studied: A review of 13 small studies with 30 participants. All had disabilities. Children and adults, including school age students.
What they found: Offering a choice of activity, or of the order to do tasks in, cut problem behavior by amounts doctors call meaningful. Results ranged widely from child to child. Some hit zero problem behavior often. Others barely moved.
What it means for you: A child who will not start gets to pick the mission order first. That is our standard move. These were disability studies in schools, so we never quote these numbers for a typical child at home.
Picking from two held young kids longer than picking from six or seven.
Moderate
Maimaran (2017), Judgment and Decision Making 12(3), 198 to 207.
Moderate: three consistent experiments with direct engagement durations and a built-in null control, but preschoolers only, so it licenses the band's lower edge as an extrapolation, not a measurement
Who was studied: Three experiments with children ages 4 to 5. Below our band. Groups ran from 42 to 59 children.
What they found: Children who picked a book or game from a set of two played with it longer. Picking from the big set also took longer and felt harder. The children said they preferred the big set. Set size changed nothing about how much of a chosen snack they ate, so the effect sits in engagement, not in everything.
What it means for you: Decision points offer two options, most of all at ages 5 to 6. A wall of options is not freedom. It is a leak. This was measured in preschoolers, so we claim it for the band's lower edge only.
Pushy control breeds pushback. The chain is measured. In teens.
Thin
Van Petegem, Soenens, Vansteenkiste & Beyers (2015), Child Development 86(3), 903 to 918.
Thin (for this product): the mechanism evidence is strong in design (four studies, clinical and community samples, a vignette experiment) but every sample is 12 or older; it anchors the mechanism, it cannot size the effect at 5 to 10
Who was studied: Four studies with 1,472 young people, ages 12 to 21. Above our band.
What they found: Controlling parenting came first. Then came the felt pressure of the young person. Then came defiance and acting out. Warmth and clear rules did not explain it away. Control itself carried the effect.
What it means for you: When a child defies a pushy instruction, we read it as a predictable answer to pressure. It is not a character flaw. Parent scripts strip the pressure out and keep the rules. Nobody has sized this effect at ages 5 to 10, and we say so.
Kids who get bored a lot are the kids who switch gears slowly.
Moderate
Zhao & Uehara (2025), Frontiers in Psychology 16:1579642.
Moderate: in-band, executive function measured by performance rather than report, but a small exploratory sample, boredom measured by single-item parent ratings, and two cultural contexts only
Who was studied: 89 children, ages 6 to 8, in Japan and China. Their thinking skills were tested directly. Parents rated daily boredom.
What they found: Children with slower switching between rules were rated as bored more often in daily life. The link held across all three language groups. Boys reported more boredom during the test tasks themselves. Memory span and self control showed no link to boredom at all.
What it means for you: A boredom-prone child gets missions with more switches, variety, and rule changes built in. The link runs through switching, so the design answers it. This study shows a link, not a fix. Nobody has shown that training switching cures boredom.
The kids glued to screens are the boredom-prone ones.
Moderate
Uehara & Ikegaya (2025), Frontiers in Psychology.
Moderate: a decent sample, squarely in-band, with large group differences; correlational, mother report only, one country, and 301 of the mothers also appear in a companion study from the same lab
Who was studied: 341 mothers in Japan reporting on children in grades 1 to 3. Average child age was about 8.
What they found: Children whose longest focus and favorite play were online scored far higher on boredom tendency. They scored lower on focus tendency. Attention difficulties also ran higher in the online groups. Mothers who got bored easily had children who leaned online too.
What it means for you: "He concentrates longest on a screen" reads as a boredom signal to us. That profile gets fast starting, high energy missions. We do not claim screens cause the boredom, or boredom causes the screens. This study cannot say which way it runs.
Boredom-prone kids hate waiting. The wait itself is part of why focus slips.
Moderate
Hsu, Chen, Ni, Chueh & Eastwood (2025), Frontiers in Psychiatry 16:1526089.
Moderate: two informants, a clinical comparison group, validated scales; but a clinical sample, correlational mediation, and most of the age range sits above the band
Who was studied: 183 young people, ages 9 to 16, in Taiwan. Half had ADHD. Half did not. Only ages 9 to 10 sit inside our band.
What they found: The ADHD group scored higher on boredom and on hating delay. Boredom, delay hatred, and inattention all moved together. In parent ratings, hating delay carried part of the path from boredom to inattention.
What it means for you: For a boredom-prone child, missions start fast and pay off early. No long build-up before anything happens. Waiting time inside a mission gets filled, not left empty. This was a clinic sample, so no pack language ever screens for or treats attention problems.
Some kids are bored everywhere. Homework was the worst spot of all.
Thin
Larson & Richards (1991), American Journal of Education 99(4) (article title: "Boredom in the middle school years: Blaming schools vs blaming students").
Thin (for this product): foundational and still the reference point for trait boredom in youth, but above the band, three decades old, and entered here on a secondary summary pending re-check
Who was studied: Students in grades 5 to 9, paged at random moments for one week. Mostly above our band. This entry rests on a later summary, not the original paper.
What they found: The same students reported boredom at school and away from school. Boredom looks like a trait the child carries, not just an answer to one dull setting. Homework and schoolwork drew the most boredom, about 40 percent of reports. Even creative activities drew about 30 percent.
What it means for you: When a parent says "he is bored everywhere," we believe it is information about the child. Good activities will still meet boredom sometimes, creative ones included. We do not quote these percentages as facts about 5 to 10 year olds. The original paper needs a fresh check first.
Interest alone does not make a young child stick. Self control has to come with it.
Moderate
Torgrimson, Tan & Grammer (2021), Journal of Experimental Child Psychology 208, 105141.
Moderate: in-band, a behavioral persistence measure, and a clean moderation pattern, but one small single-site sample
Who was studied: 73 children, average age about 7, working on a hard puzzle task.
What they found: Interest and feeling able turned into sticking power only in children with fair to strong impulse control. Children low on impulse control quit sooner at the same interest level. Girls stuck longer than boys at equal motivation.
What it means for you: For ages 5 to 7, sticking power is built into the task shape. One clear thread. A visible next step. Nothing else competing for the eyes. A child who quits was not necessarily bored. Interest was there in the quitters too.
How long a 9-year-old sticks at a hopeless puzzle tracks his childhood, not just his grit.
Moderate
Whipple, Genero & Evans (2016), Journal of Applied Research on Children 7(1), Article 4.
Moderate: in-band behavioral measure and a longitudinal design, but a mostly white rural sample, and statistical mediation is not causal proof
Who was studied: 206 children in rural New York, followed from birth to age 23. Sticking power was timed at ages 9 and 13 on a puzzle that could not be solved.
What they found: The more of childhood a child spent in poverty, the less time he stuck at the puzzle. Sticking time then carried part of poverty's link to school confidence at 17 and to education level at 23. The sample was mostly white and rural. Numbers like these show a pathway. They do not prove cause.
What it means for you: A quitting point tells us about fit and load. It never earns a child a label. Hard missions build in early wins, so sticking gets practiced instead of just demanded.
Stick-with-it behavior can be taught. Kids then pick the hard task and retry after failing.
Strong
Alan, Boneva & Ertac (2019), Quarterly Journal of Economics 134(3), 1121 to 1162.
Strong for malleability and difficulty choice in band: two RCTs, a behavioral incentivized measure, effects replicating across samples; school context and a disadvantaged urban sample bound the claim
Who was studied: Over 3,200 fourth graders, ages 8 to 10, in 52 schools in poorer parts of Istanbul. Two separate randomized trials.
What they found: Teachers taught a short course on effort and setbacks. Taught children picked the harder task more often. They retried more after a failure message. They succeeded 8 to 10 points more often and earned 16 to 26 percent higher rewards. Math scores rose and still showed a gain two and a half years later.
What it means for you: Missions coach the retry out loud. A failed first try is a normal scripted step, with a visible second try after it. Harder levels carry a real payoff difference. We never promise a pack builds lifelong grit as a trait. This study changed behavior inside a taught classroom, which is a smaller and truer claim.
Unfinished tasks are not remembered better. People do go back to them.
Strong
Ghibellini & Meier (2025), Humanities and Social Sciences Communications 12, article 962.
Strong (as a correction): the definitive synthesis of this literature, and it reverses the memory half of an existing entry in the list of studies
Who was studied: A review of 59 published studies. Most used adults. Child studies sit inside the return-to-task pool, and their numbers cannot be split out.
What they found: Across the record, interrupted tasks were remembered no better than finished ones. The famous memory effect failed. The return effect held firm. People resumed an interrupted task about 67 percent of the time, and more often when the task was attractive.
What it means for you: This review corrects the old entry on unfinished tasks. Pause points and a visible half-done mission earn their place because kids come back, not because kids remember. No card will ever claim an open mission stays in a child's memory.
For 7 to 9 year olds, challenge and complexity pull kids in more than feedback does.
Thin to Moderate
Inal & Cagiltay (2007), British Journal of Educational Technology 38(3), 455 to 464.
Thin to Moderate: directly in band and in a play context, but a small single-site sample and an interview measure adapted on the fly; no experience sampling study of flow exists in this age band (see empty results below)
Who was studied: 33 children, ages 7 to 9. They played games one hour a week for six weeks and were interviewed about feeling absorbed.
What they found: The children did report deep absorption. Challenge and complexity drove it most. Clear feedback mattered less. Game mechanics weighed more for boys and the story frame more for girls, but those groups were tiny. Some flow questions had to be dropped because children this age could not grasp them.
What it means for you: When a mission is not holding a 7 to 9 year old, we turn the difficulty and complexity dials first. Clear feedback is basic upkeep, not the draw. This study shows which way the lever points. It does not find the perfect setting.
"This will be graded" made kids pick easy puzzles and enjoy them less.
Moderate
Harter (1978), Child Development 49(3), 788 to 799.
Moderate: a clean experimental contrast on the exact behavior PGP cares about (chosen difficulty), discounted for the above-band sample and 1978 vintage
Who was studied: Sixth graders, ages about 11 to 12. Just above our band.
What they found: Children chose how hard their word puzzles would be. The group told their work would be graded picked easier puzzles. They also smiled less after solving. The group told it was a game picked harder ones. Each group knew it would have chosen the other way under the other framing.
What it means for you: Scores, streaks, and grades stay off the child's side of a pack. Difficulty is offered as a game choice. A child should never be able to fail in public at a level he picked.
The fun sits in solving something hard. Repeating a solved one drains it.
Moderate
Harter (1974), Child Development 45, 661 to 669.
Moderate: direct behavioral affect measurement on the difficulty question, discounted for age position and a single paradigm from 1974
Who was studied: Children in grades 5 and 6, ages about 10 to 12. At and above the top of our band. They worked word puzzles of rising difficulty.
What they found: Children smiled more on puzzles they solved than on ones they failed. Among solved puzzles, the harder the puzzle, the bigger the smile. Repeating a puzzle already solved made the smiling fade.
What it means for you: Missions climb in difficulty while success stays in reach. A mastered mission gets retired, not repeated as filler. Easy wins alone do not hold children. This study measured that directly.
After failure, kids split two ways. One group blames itself. The other hunts for a fix.
Strong
Diener & Dweck (1978), Journal of Personality and Social Psychology 36(5), 451 to 462
Strong for the existence of the two patterns at the top of the band: direct continuous observation across two studies; discounted because the sample sits at age 10 to 11 and the paradigm is a laboratory discrimination task
Who was studied: 130 fifth graders, about ages 10 to 11. Researchers sorted them first into helpless and mastery-minded groups, then listened to everything they said aloud.
What they found: Before failure the two groups performed the same. After failure the helpless group blamed low ability and felt worse. Their strategies got worse and worse. The mastery group barely blamed anything. They talked themselves through checks and fixes, and their strategies held or improved.
What it means for you: Cards carry a next step prompt after any fail point. Failure is framed as news about the attempt, never about the child. Parents can watch which pattern their child shows. Does he give up and blame himself, or regroup and retry? So we may ask about it as behavior. Never call a mission "for smart kids" near a fail point. The groups were equal before failure, so a helpless answer is not low ability.
Shielding a failure-shy child with easy wins did not repair anything. Failing safely with coaching did.
Moderate
Dweck (1975), Journal of Personality and Social Psychology 31(4), 674 to 685
Moderate: a genuine experiment on exactly the target behavior, but N of 12 and from 1975; treat as design direction, not an effect size
Who was studied: 12 children, ages 8 to 13, picked out by school staff for extreme reactions to failure. A tiny sample, and it reaches above our band.
What they found: One group got success-only practice. After training they still fell apart at failure. The other group got real failure inside training, plus coaching to blame effort instead. That group held or improved after failure and changed how they explained it.
What it means for you: Packs may hold survivable failure points on purpose, with effort and strategy words built in. A child who melts down at failure does not get an all-wins pack. And we stay humble here. The repair training was intensive and led by an adult. Words on a card alone are not that training.
Toddlers who hung back still hung back at 7, when a new group game shut them out.
Moderate
Walker, Henderson, Degnan, Penela & Fox (2014), Social Development 23(3), 487 to 501
Moderate: in-band outcome age with direct observation; the trait was measured in toddlerhood, so it speaks to stability of the disposition, not to a parent rating taken at age 7
Who was studied: Children followed over years. Shyness was measured at ages 2 to 3 by mothers and by lab watchers. Social behavior was watched at age 7 in a live game with strangers that turned excluding.
What they found: The more a toddler hung back from new things, the more he withdrew at 7. He also came up with fewer bold solutions to the social problem. This was one new session only. The study never timed how long warming up takes.
What it means for you: New social missions open slow on purpose. Watching first is allowed. Joining late is allowed. A slow starter may still be finding his feet deep into a first session with new people. We never quote a warm-up time in minutes. No study here measured one.
Shy behavior follows steady paths. Many slow starters do not simply warm up and catch up.
Strong
Poole, Degnan, Harrewijn, Almas, Fox & Henderson (2022), Child Development 93(5), 1334 to 1346
Strong for the shape of the phenomenon across the exact band: repeated direct observation at 5, 7, and 10; the task is a speech performance, so transfer to play formats is an inference
Who was studied: 227 children. Each gave a short speech at ages 5, 7, 10, and 13 while researchers watched. Shyness was measured at ages 2 to 3.
What they found: Three paths showed up. One group stayed high in shy behavior. One group rose over time. One group stayed low. Strong early shyness pointed to the high steady path. Only about half of the teens with social anxiety had been shy toddlers, so early shyness is one road, not a gate.
What it means for you: We never assume a slow starter joins in by the third try. The kinder design repeats the same gentle shape with new fill, instead of throwing new formats at him. And one hard first session measures nothing about a child. We judge across several outings.
What set struggling kids apart was not bigger blowups. It was slower calming down.
Thin
Scheper, Majdandžić, van de Ven, Jansen, Doreleijers, Schuengel & de Vries (2017), Child Psychiatry and Human Development 48(6), 841 to 850
Thin for this product: the recovery construct and its parent observability are directly supported, but the sample is young and clinical; take the direction and the separability, not the sizes
Who was studied: 115 children referred for emotional and behavior problems, matched with 115 children from the general public. Ages 3 to 7, mostly below our band. Parents filled in a temperament form.
What they found: The two groups reacted with the same overall strength of bad feeling. One part differed. The referred children calmed down more slowly after upset. That slower calming also tracked with more anxiety and acting out problems.
What it means for you: We ask parents two separate questions. How big is the blowup. And how long until he is himself again. They are different facts. Packs build in a calm way back in after a hard moment. We take the direction from this study, not its numbers, since the children were young and in clinics. Slow calming is a pace to design around, never a defect to fix.
