**The evidence does not support the broad claim that daycare children are “often antisocial and emotionally unstable.”** Some studies have found small increases in particular behavior problems; findings vary with the study, care setting, and outcome measured.

“Antisocial” also needs unpacking. Researchers usually measure *externalizing behaviors*, such as aggression, disobedience, or impulsivity. Those findings do not establish that children become withdrawn or unable to form relationships.

Three studies help explain the picture:

- **The US NICHD study followed children from infancy.** Its 2010 follow-up found that more hours of nonparental care were associated with slightly greater impulsivity and risk-taking at age 15. Higher-quality care was associated with fewer acting-out problems. The differences were small, and this observational study could not establish that childcare caused them. [Vandell and colleagues, 2010](https://pmc.ncbi.nlm.nih.gov/articles/PMC2938040/)
- **A newer analysis combined seven studies involving 10,105 toddlers and preschoolers across five countries.** It examined whether changes in a child’s daycare hours predicted changes in that same child’s behavior. It found no association between hours and externalizing problems. This strengthens the evidence against a simple “more daycare causes more aggression” claim, although it does not directly settle the question of starting daycare at eight months. [Rey-Guerra and colleagues, 2023](https://academic.oup.com/chidev/article-abstract/94/2/458/8255149)
- **Research specifically on infants examined attachment at 15 months.** The NICHD researchers found no overall effect of childcare attendance on attachment security. They did find increased insecurity in combinations involving less responsive parenting and poorer-quality care, more hours, or multiple care arrangements. That points to the importance of the child’s overall caregiving environment. [NICHD Early Child Care Research Network, 1997](https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1467-8624.1997.tb01967.x)

For your decision, **the quality of the actual care available deserves close attention**. Look for warm, responsive caregivers who comfort your son, small groups, and stable staff. The American Academy of Pediatrics identifies these as key indicators of quality. Your family’s finances and both parents’ preferences also belong in the decision. [AAP guidance](https://www.healthychildren.org/English/family-life/work-and-child-care/Pages/why-quality-matters-in-early-child-care-aap-policy-explained.aspx)

As for the “meh” first week: separation anxiety commonly develops around this age. One week gives you limited information about how he will settle. Ask staff how he behaves after drop-off, whether they can comfort him, and how he feeds, sleeps, and engages during the day. A predictable goodbye routine can help. [AAP separation guidance](https://www.healthychildren.org/English/ages-stages/toddler/Pages/Soothing-Your-Childs-Separation-Anxiety.aspx)

**These studies do not establish that your wife needs to leave her job to protect your son’s emotional development.** They support evaluating the care he receives and how he responds over time.