Human Infancy: An Evolutionary Perspective

ability active adaptive adult aggression animals appear average babies become behavior birth blind boys Brent Carl Caucasian changes child compared completely considered continued crying cultural dependent differences differential discussed early effects environment evidence evolutionary example exhibited experience eyes face fact fear females findings fraternal Freedman frequently function genetic girls greater hand human identical important indicates individual infants interest involved Kurt later learning less look lower major males Maria means Michael months mother motor nature newborn normal noted objects observed occur organism Oriental pairs parents patterns performance period personality play population position possible present probably question rates relatively reported response scale seems seen selection showed similar smiling social species stimuli strangers tended traits turn twins University usually variation visual voice whereas young