Small (Our Babies, Ourselves), a Cornell University anthropologist, compares Western child-rearing practices with those of various non-Western peoples, as well as other mammals, in an effort to "go beyond the narrow confines of one culture, one socioeconomic class, and one species." Where her previous book explored the way culture shapes parenting during an infant's first year, this sequel examines the impact of culture on children's development of language, knowledge, moral reasoning, social roles and gender identity. Much of the book is devoted to scientific claims (especially those deriving from evolutionary biology and psychology) about childhood, a developmental stage unique to humans. She observes some disparities between "expert" and parental knowledge: apparently child development researchers assume "that kids all over the world are essentially the same," yet even among parents in the West, "[t]here is no consensus on the nature of the child." Small also challenges some widely held contemporary Western beliefs, arguing, for example, that although the nuclear family is "accepted in this culture as the 'best' family environment for children," there are many advantages to extended families and other forms of communal child rearing. Unfortunately, she has a tiresome knack for stating the obvious ("a child brought up on a rural farm in Kenya is different in most ways from a child brought up in an upper-class household in America"; "the brain is surely one of the big mysteries of science"). Although Small's book is admirably ambitious, it is science lite and may frustrate any reader who has given serious thought to its subject. (Apr.)