# Day 306: Looking for the hidden toy

> By 10 months a baby keeps searching for a toy they saw you hide, and by a year most find it. The classic two-cup study, and the game that proves memory: the two-cup hide.

- Series: Your eleventh month, day by day (https://chorevia.com/learn/eleventh-month), day 306 of 365, week 41
- Canonical URL: https://chorevia.com/learn/eleventh-month/day-306
- Last reviewed: 2026-10-21
- Publisher: Chorevia (https://chorevia.com)
- Cite as: Chorevia. "Day 306: Looking for the hidden toy." Last reviewed October 21, 2026. https://chorevia.com/learn/eleventh-month/day-306

This guide is general education that summarizes published research and guidance from groups like the American Academy of Pediatrics, the CDC, and the WHO. It isn’t medical advice, and every child develops on their own timeline. Your pediatrician knows your child; if something feels wrong, call them. In an emergency, call 911.

A toy that disappears under a cloth used to stop existing. Around now it goes on existing, and your baby goes looking. Today is object permanence at ten months, the study everyone cites, and the game that shows the memory working.

## Heart

By 1 year, most babies look for things they saw you hide ([CDC](https://www.cdc.gov/act-early/milestones/1-year.html)). The AAP's timing is finer: by about 8 months, your baby will lift a scarf to find a hidden toy, and by 10 months they'll keep searching, because they now know objects exist out of sight ([AAP](https://www.healthychildren.org/English/ages-stages/baby/Pages/Cognitive-Development-8-to-12-Months.aspx)). Your baby is 10 months old. So the scarf version is probably old news, and the version where the toy is gone for a few seconds and still gets hunted for is the one arriving.

## Head

The classic study used two hiding places. Babies 7.5 to 9 months old who watched a toy move to a new spot still searched in the old spot after delays of just 2 to 5 seconds, while 12-month-olds made the same mistake only after delays of more than 10 seconds ([Diamond & Goldman-Rakic, 1989](https://pubmed.ncbi.nlm.nih.gov/2924839/)). Your baby is between those two groups, so expect the old-spot mistake some of the time, and expect it to shrink over the next weeks. The mistake isn't a failure of memory; it's memory losing a race against habit, and the race gets closer every week. The guide's activity is [Where did it go?](https://chorevia.com/learn/7-12-months#where-did-it-go), and next year's is [Hide-and-find](https://chorevia.com/learn/1-year#hide-and-find).

## Body

CDC and the AAP both suggest hiding games at this age ([CDC](https://www.cdc.gov/act-early/milestones/9-months.html); [AAP](https://www.healthychildren.org/English/ages-stages/baby/Pages/Cognitive-Development-8-to-12-Months.aspx)). Today's uses two identical cups instead of two cloths, which makes the second hiding place a real test of memory rather than a test of which cloth looks different. Use cups too big to fit entirely in the mouth ([AAP](https://www.healthychildren.org/English/health-issues/injuries-emergencies/Pages/Choking-Prevention.aspx)), and a toy too big as well.

## Try today

### The two-cup hide

- **Time:** 2 to 5 minutes
- **From the guide:** [Where did it go?](https://chorevia.com/learn/7-12-months#where-did-it-go)

1. Sit facing your baby with one small toy and two identical plastic cups. Let them watch you put the toy under the left cup. Ask, "Where did it go?" and cheer when they find it ([CDC](https://www.cdc.gov/act-early/milestones/1-year.html)).
2. Do it under the left cup three or four times, until it's easy.
3. Now, with their eyes on your hand, put the toy under the right cup. Wait 2 seconds, then let them search.
4. If they go to the left cup, don't correct; lift the right one, show the toy, and try again. The old-spot mistake at this age is the study's finding, not a problem ([Diamond & Goldman-Rakic, 1989](https://pubmed.ncbi.nlm.nih.gov/2924839/)).
5. Stop while it's still fun. Try again in a week and see if the right cup wins more often.

**Make it work:** Cups and toy both too big for the mouth ([AAP](https://www.healthychildren.org/English/health-issues/injuries-emergencies/Pages/Choking-Prevention.aspx)). A toy that squeaks under the cup makes the game too easy and twice as fun; use it on a tired day.

## Watch for

- **Normal:** a baby who lifts the old cup, finds nothing, and chews it; searching the old spot after short delays is what the study found at this age ([Diamond & Goldman-Rakic, 1989](https://pubmed.ncbi.nlm.nih.gov/2924839/)). **Bring it up** if by 12 months your baby doesn't look for a toy they saw you hide ([CDC](https://www.cdc.gov/act-early/milestones/1-year.html)).
- **Normal:** a cup thrown across the room instead of lifted. **Go to the ER now** if your baby is hard to wake, isn't alert when awake, or seems confused ([AAP](https://www.healthychildren.org/English/tips-tools/symptom-checker/Pages/symptomviewer.aspx?symptom=Fever)).
- **Normal:** a day of no interest in any game with a low fever and a runny nose. **Call within 24 hours** if your baby has a fever with no other symptoms for more than 2 days, any fever that lasts more than 3 days, or a fever that comes back after a day without one ([AAP](https://www.healthychildren.org/English/tips-tools/symptom-checker/Pages/symptomviewer.aspx?symptom=Fever)).

## For you

The game that proves memory also explains the door. The same baby who now knows a toy exists under a cup knows you exist when you're gone, and has little sense of how long gone is; the AAP calls the crying that follows a sign of attachment ([AAP](https://www.healthychildren.org/English/ages-stages/baby/Pages/Emotional-and-Social-Development-8-12-Months.aspx)). It's one skill, pointed at a duck and then at you. The cup comes off and the duck is there. The door opens and you're there. Say a quick, cheerful goodbye every time instead of sneaking out ([CDC](https://www.cdc.gov/act-early/milestones/9-months.html)), and the memory you're building is that hidden things come back.

If you're the partner: you're the cup today. Step behind the door for a count of five and come back saying "Here I am," three times. It's the same game, and you're the better toy.

## Sources

- Centers for Disease Control and Prevention. "Milestones by 1 Year." Learn the Signs. Act Early. program, updated 2026. https://www.cdc.gov/act-early/milestones/1-year.html
- American Academy of Pediatrics. "Cognitive Development in Infants: 8 to 12 Months." HealthyChildren.org, updated 2023. https://www.healthychildren.org/English/ages-stages/baby/Pages/Cognitive-Development-8-to-12-Months.aspx
- Diamond A, Goldman-Rakic PS. "Comparison of human infants and rhesus monkeys on Piaget's AB task: evidence for dependence on dorsolateral prefrontal cortex." *Experimental Brain Research*, 1989. https://pubmed.ncbi.nlm.nih.gov/2924839/
- Centers for Disease Control and Prevention. "Milestones by 9 Months." Learn the Signs. Act Early. program, updated 2026. https://www.cdc.gov/act-early/milestones/9-months.html
- Bradin S. "Choking Prevention for Babies & Children: What Every Parent Needs to Know." HealthyChildren.org, updated 2026. https://www.healthychildren.org/English/health-issues/injuries-emergencies/Pages/Choking-Prevention.aspx
- American Academy of Pediatrics. "Fever" (symptom checker). HealthyChildren.org, accessed 2026. https://www.healthychildren.org/English/tips-tools/symptom-checker/Pages/symptomviewer.aspx?symptom=Fever
- American Academy of Pediatrics. "Emotional and Social Development: 8 to 12 Months." HealthyChildren.org, updated 2009. https://www.healthychildren.org/English/ages-stages/baby/Pages/Emotional-and-Social-Development-8-12-Months.aspx