Parents, especially those raising a first child, will value these three volumes which describe behaviors common for two-, three-, and four-year-old children. Ames and Ilg's approach--""informed permissiveness""--respects a child's timetable while acknowledging adult priorities too. They tell what patterns of action are most likely to occur and give advice on how to avoid or resolve some of the thornier problems. They suggest that children who are tender at two may be terrible six months later, given to tantrums and negative responses. Favorite words are ""mine"" and ""no."" Most need much help during peer group play--twosomes are best. Give them choices and second chances. At three they're conforming; at three and a half they're contrary, mostly to mother. ""No"" is replaced by ""I don't want to:"" Many have favorite stories and memorize the words. Four is the age of silliness, exaggerations, telling lies. Fine and gross motor skills improve and cooperative play is possible. Some children struggle with distinctions between the real and the imaginary. ""Why"" questions proliferate. The authors emphasize that human life is variable, that patterns exist but no child follows them at regular rates; a child who walks early may be slow to talk or move timidly a few months later. They insist that parents resist teaching cognitive skills (Ames co-authored Don't Push Your Preschooler) and concentrate on sharing experiences. Throughout these books, the authors describe parents in traditional roles--e.g., a homemaker mother is indulgent about table manners while the working father is strict on the same issue--and this bias will limit their appeal. The books give reasonable information about each age group, although Your Four-Year-Old limits its discussion of individuality to William Sheldon's classification of body types and personalities. Helpful appendices list toys and books for the children and additional reading for adults.