The birth of a younger sibling can be a traumatic event for the older child. Unquestionably it places increased demands on parents and causes important changes in the inner balance of the family. Childrearing manuals are full of advice about how to get through this difficult time. But until now such advice has been based more on clinical guesswork than on direct observation of what really happens to families when a sibling is born.

With the arrival of "Siblings," this gap in our knowledge is admirably filled. Judy Dunn and Carol Kendrick studied forty families for a period of approximately one year starting shortly before the birth of a second child. Some families, they found, weather the storm much better than others, and their book examines the full catalog of factors that can make the difference. There are, for instance, parenting styles that ease the impact on the older child, improve relations between siblings, and generally make life easier for the entire family. But there are also differences among children in such characteristics as sex, age, and temperament, all of which have a major influence totally beyond parental control.

Despite the undeniable stress involved, Dunn and Kendrick demonstrate that the advent of a sibling can be a stimulus for real cognitive and emotional growth on the part of the older child. No longer "the baby," the child must try to deal with a newcomer whose attempts to communicate are necessarily rudimentary. Siblings shows how the elder child's efforts to understand the baby can form the basis for a loving bond of extraordinary durability.

A sensitive and informative book, "Siblings" takes psychology into an area of family life and child development that has long received too little attention.