Research has not established an ideal age to start preschool. For your two-year-old, consider whether the program would give him better care and learning opportunities than his current arrangement. There is no need to enrol him at two solely for an academic head start, though his age is also no reason to rule out a good toddler program.

“Nursery,” “preschool,” and “school” mean different things in different countries. A toddler program built around play and attentive care can be quite different from a classroom where children are expected to sit through formal lessons.

Two studies help explain what the research can tell us:

- A large US study found that children who started centre-based care between ages two and three had larger reading and maths gains at kindergarten entry than those who started earlier or later. It also found some less favourable social-behaviour ratings, particularly among children who started earlier. Because the study was observational, differences between families and programs prevent it from establishing that starting at two or three caused these outcomes. [Loeb and colleagues, published in 2007](https://www.nber.org/papers/w11812).
- The NICHD longitudinal study found that higher-quality care was associated with modest improvements in language, cognition, and some social outcomes. Family characteristics were generally stronger predictors. These findings also describe associations; they do not establish an ideal starting age. [Research summary](https://pubmed.ncbi.nlm.nih.gov/16478355/).

When you visit a program, look for:

- Warm, responsive teachers who have experience caring for two-year-olds.
- Small groups with enough adults to give each child individual attention.
- Plenty of time for play, conversation, stories, music, and movement.
- Care that accommodates his naps, toileting needs, and need for comfort when upset.

The [American Academy of Pediatrics’ childcare guidance](https://www.healthychildren.org/English/family-life/work-and-child-care/Pages/choosing-a-child-care-center.aspx) and [NAEYC’s guidance on developmentally appropriate education](https://www.naeyc.org/resources/position-statements/dap/contents) support these priorities.

If childcare is optional, you could start gradually with shorter sessions. That is a reasonable practical approach, though research has not established it as the best one. Watch how he settles with the caregivers and how he engages over time. Your choice will depend on his needs, the program, the hours he attends, and the care available at home.