Babies & Social Judgments
Some creative research covered by the AP is suggesting that even the youngest humans can make discriminating social judgments. It appears that infants as young as 6 months will prefer someone who is helpful rather than harmful. This has sparked a debate about whether this shows some inherent social ability or whether this was still behavior learned in the first 6 months of life.
This is a nice representation of the oldest debate in all of psychology: nature v. nurture. Based on what we are learning about evolution, my view is that our biology allows us to have the skills to learn social behavior as early as these ages, and that the life experience of the child up to that point would be a large reason for their choosing the helpful other.
Meek, W. (2007). Babies & Social Judgments. Psych Central. Retrieved on September 3, 2015, from http://psychcentral.com/blog/archives/2007/11/23/babies-social-judgments/