Credits: Brain Scans, Figure 1 from: Knickmeyer, R. C.; Gouttard, S.; Kang, C.; Evans, D.; Wilber, J.; Smith, K.; Hamer, R. M.; Lin, W.; Gerig, G.; & Gilmore, J. H. (2008). A structural MRI study of human brain development from birth to 2 years. The Journal of Neuroscience, (28)47, 12176-12182; Real People: Black African American Toddler Boy Orange Hat Galoshes Thinkstock; Small child, Jaroslaw Wojcik/Getty Images; Baby boy (12-15 months) close-up, portrait, Photodisc/Getty Images; Baby boy eating, © sanapadh/Alamy; Baby learning to stand assisted by a stoll, Aseph/Shutterstock; Little boy playing with colorful cubes, Sergiy Bykhunenko/Shutterstock