"The most important thing to learn in life," said child psychologist Bruno Bettelheim, "is how to stretch according to the covers."

To those unfamiliar with the 77-year-old author, educator and concentration camp survivor, this hardly sounds like the wisdom of the ages. But the 600 therapists, social workes and educators at a University of Nebraska conference on "Building Family Strengths" knew better.

"My old grandmother told us children this philosophy," recalled Bettelheim. "When she was small, all the children slept in one bed -- so they learned about give and take. If you grabbed too much of the cover you got a kick and couldn't sleep.

"In Japan the whole family sleeps in one room . . . as they did in the proverbial log cabin where Lincoln was raised. But today we think that's terrible because of all the 'space' we all need.

"If you need all that separateness, fine. I won't pass judgment. Just don't get married and don't have children."

The renowned psychologist -- who now teaches at Stanford and is professor emeritus at the University of Chicago -- was a particularly appropriate keynote speaker for the convention focusing on practical solutions to family problems.

Author of numerous books, including Love Is Not Enough and his most recent Surviving, Bettelheim's scholarly, yet common-sense view of family life enchanted an almost worshipful audience. The crowd particularly seemed to enjoy several anecdotes from his Viennese childhood, which he recounted to illustrate his talk on "the difficulties between parents and children." (Usually caused, he said, by family members expecting too much of each other.)

"My grandmother had 11 living children. One of them, I know now, was schizophrenic. I challenged her -- being age 4, precocious and not very polite -- what did she think of this son of hers who acted funny?

"She said -- and I translate roughly -- 'One out of 11 is a good batting average.' How come my 84-year-old grandmother with a seventh-grade education knew that not everyone can be perfect, and accepted with equanimity that one of her sons was crazy.

"It didn't hurt her, upset her or shake her confidence in herself. Yet modern, well-educated parents who know all the laws of statistics can not accept this . . . and they ruin their own life and their child's life by completely unreasonable expectations."

In Bettelheim's youth, delinquent children were often sent away to start their lives anew. "My relatives knew what to do with a delinquent family member. We took up a collection and shipped him off to the United States . . . where he grew up to be imminently successful.

"Nowadays if a child tries to run away, we send a truant officer after him, or -- depending on the financial conditions of the family -- a psychiatrist. We send him right back to the situation from which he tried to escape, for good reason, because it was unbearable to him."

In those days, the family was saved from the unpleasant truth "that the difficulties of children are caused by their parents. Such a truth should be carefully hidden rom everybody, most of all the parents. It doesn't do them any good and it doesn't do the child any good."

A "large number" of delinquent children, said Bettelheim, misbehave "just to punish their parents." Modern parents, in turn, often feel guilty and "take it out" on the child.

Unlike Bettelheim's relatives, today's parents are more aware, he said, "that it is what the child observes in growing up that will condition -- for better or for worse -- all his later life."

Demographic, economic and social changes also play a part, he said, "in making it difficult for children and parents to live together.

"The onset of maturity, as judged by a girl's first menstrual period, was 14 years and three months at the beginning of the century and about 16 years the century before that. Today it is closer to 12. One shudders to think what the situation might be in the next hundred years."

Children used to attend school from about 6 to 13, then were expected to earn their keep. Now they start school as early as 3 and finish in their late teens or early 20s. "We still have no curriculum for the 11th and 12th grade," he noted. "They were added during the great Depression to keep them out of the labor force."

So while today's children are "sexually mature earlier, physically healthier and probably more intelligent," he said, "we treat them as children and keep them dependent on us way beyond reason. Then we wonder that nothing but conflict occurs."

Also, shorter lifespans years ago meant that "by age 13 or 14 one parent was already dead. It's very hard to get into conflict with a dead parent. Usually the dead parent was glamourized as the epitome of all good qualities. Nowadays we live to demonstrate that ain't so."

Attempting to build a family's relationship around love, said Bettelheim, is another unreasonable expectation. "Only one of the 10 Commandments speaks about the relationship of the child to the parents . . . honor thy father and thy mother. The Lord in His infinite wisdom didn't order us to love that parent -- He knew it was asking too much.

"The family was never meant to be built on love. It was meant to be a mutually protective society -- either working together or starving singly. The children were the great economic advantage of a family.

"By working with their parents, children got to know and respect them . . . and it's easy to love someone you respect. We all enjoy teaching our children and being admired by them. So we couldn't help but love them."

In addition to unreasonable expectations about each other, Bettelheim said families also create problems by having unreasonable expectations about life.

"We expect everything to go smoothly and easily, and think that something is wrong if we run into a problem. That's the worst view a family can have. If we read the scriptures, a life is three score and 10 of blood, sweat and tears.

"A family doesn't prove itself through having a good time together. Your worst enemy will be willing to have a good time with you. You need your family when things are rough. Then children know what a parent is here for -- to bind up the wounds, particularly the psychic ones."

Although parents teach children "to uplift the downtrodden," he said, "when a child comes home having failed a test or getting a very low score on the college entrance boards, do we uplift his spirits -- or do we tell him 'You should have studied harder,' as if the kid didn't know that?

"Realize," he told his audience in a voice both kind and commanding, "that you can prove your worth to your mate or to your child only when things have gone wrong . . . by sticking together and making things right.

"That's the best thing we can give our children, the hope and conviction that even when things get tough we'll be able to cope."