Human sacrifice -- and, in particular, infant sacrifice -- may be the dawn-of-time precursor of the taboo against praising a child. We don't want to push our luck, the gods may turn against us, against the whole community. If we act as though our delicate and precious and utterly amazing offspring were nothing much, maybe God will give it health and long life. We have avoided the presumption that our child may be better, smarter, handsomer, or stronger than others in the community.

Another source of the taboo against praising your child is the notion that praise will go to her head: she will know she's smart, he will know he is good-looking. Both will become conceited and resented by the community as a result of this knowledge. Parents down-pedal their offsprings' talents and strengths in public, not wanting to show off too much (although grandparents are allowed some leeway vis-a-vis their grandchildren). But, more importantly, they often don't express praise and admiration for their children's talents and strengths in private, to their child's face, where over-pridefulness is not at issue.

Make no mistake, children of all ages never tire of hearing praise from their parents. In my interviews with adult children, a recurring theme was parents' failure to validate or even to recognize their children's accomplishments, including the ongoing stuff of their lives.

The importance of praise -- sometimes referred to as strokes -- cannot be overstated. But there are problems in giving compliments. Flax and Ubell point out that "the trouble with these compliments is that they carry a hidden message." The implied message from the parents is: "I know what's good for you, and I will tell you when you are doing well. If I withhold praise, therefore, you'll know you are doing something wrong." Furthermore, even young children detect insincerity. You don't want to be caught making flattering remarks to your adult child that you don't feel. What do you say to your son when he shows you an assemblage that he has created that you think is an example of the very worst type of modern art? How do you react when your 32-year-old daughter parades her latest outfit which is an ill-fitting, stretched, and wrinkled garment that looks to you as though it came out of the free box at the homeless shelter?

Below are some guidelines relating to sincerity that should help you to give praise more freely to your adult child:

• You don't have to like something that your son or daughter does in order to give her praise. Ask her to explain web site design, rain forest action networks, or Barbie doll collector's clubs. By merely showing interest and listening to her explanations you are providing acknowledgment and validation. Your daughter will hear it as though it were praise.

• Tell him "It's you!" You wouldn't have twelve antique clocks in your living and dining rooms all ticking and bonging away at once with no let-up, but to your son, the clock collector and restorer, this is nirvana. Enjoy his uniqueness, his enthusiasm, his knowledge, his craft. He doesn't need to be like you. He needs to be himself, and would like your acknowledgment for his individuality.

• Do yourself a favor and learn about current cultural icons, trends, and changes in perception. Recognize that we are all stuck in our pasts to some extent. If you were a teenager in the '40s or '50s you may have not have noticed when the Beatles, Bob Dylan, and the Grateful Dead arrived on the scene. But for someone born in 1954 or 1958 or 1963, these musicians were larger-than-life, more than entertainment, more than dance bands. You will need to know something about the significant cultural landmarks in your child's past. You may want to bone up on the loosening of sexual mores, including co-ed dormitories and cohabitation without marriage, as well as recreational drug use, rock/rap music, and even widespread computer literacy. All of these things, and more, have influenced your adult child's life. You will need to know about them if you are going to give him validation, recognition, and praise.

• Sincerity, after all, grows out of love. If you love your adult child you can appreciate her accomplishments even if they are widely divergent from things you consider valuable or beautiful.

Ellen's daughter, Grace, threw every spare dime into equipment for her darkroom. She worked as a waitress but photography was her passion. She took close-ups of plants, the results being more-or-less geometric designs. Ellen didn't know what to make of Grace's expensive, time-consuming hobby. The pictures seemed endlessly repetitive. Grace didn't enter competitions, have gallery showings or sell any pictures. She didn't even hang any on her walls. Ellen wanted to say, "This is not leading anywhere. Try something else," but she held her tongue. She loved her 30-year-old daughter and sensed Grace's pride in her craft. She heard herself saying, one day, "I admire you, Grace, for your devotion to this work. I couldn't do it." Grace beamed.

Many parents now in their fifties and sixties grew up in homes where their parents never said "I love you" to them. This provocative finding emerged from an interview cohort of midlife parents too small to be statistically significant, but I think it is important nonetheless. Not a single interviewee remembered being told "I love you" by his or her parents even once. Why should this be so? What is it about saying, flat out, "I love you" to our children that has been shunned by many and may still constitute a taboo among middle-aged parents today?

"Do my parents love me?" is a deep and emotionally-charged question which most people would rather avoid. Either a Yes or a No answer to the question may be incomplete and unsatisfying. We can say, "Yes, of course they love me. They fed, housed, and clothed me. They raised me to adulthood. They're my parents. Of course they love me." We may also say, "My insides tell me that my parents really never loved me. At bottom I feel unloved, unwanted, not okay. Maybe they tried, maybe they were convinced that they loved me very much. But something went wrong."

Provoked by my interview data, I wrestled with the following questions: To what extent is self-esteem influenced or buttressed by the utterance of "I love you" by the parents? Further, are there functional equivalents of the three little words -- kissing, hugging, touching, and holding -- that render the words merely one variant of expression of affection? Can a child feel deeply and securely loved and appreciated without ever hearing the words "I love you" from her parents?

Many of my adult child respondents could not remember hearing the phrase used in their home. Not only did their parents refrain from saying it to the children but they also didn't say it to each other. One respondent felt there was a distinct sexual connotation to the phrase "I love you" and that fathers, especially, refrain from saying it to their daughters.

Novels, movies, indeed most cultures (both high and low) invest "I love you" with strong erotic content. Of course, we can use the phrase to express close friendships or parent-child bond. Or we can use it lightly, frivolously -- as some Hollywood stars are reputed to use the word "dahling." Nevertheless, the deep, romantic, feeling-tone of the phrase reinforces the taboo against its use by parents and adult children.

Saying "I love you" to one's sons reveals a different, though related taboo, a taboo against perceived threats to manliness. Sons, in our culture, are supposed to absorb the male values of strength, action orientation, and assertiveness, and not to place too much reliance on feeling. Over-sensitivity in males is discouraged. Saying "I love you" to boys as they are growing up may be seen as a "female" thing leading to softness, gentleness (heaven forbid), and the dreaded "sissy" epithet.

I suspect that many parents would like to tell their children openly that they love them, both in their childhood and in their adult years, but feel constrained from doing so. They may do a wide variety of things to try to convey the same message -- giving gifts, services, advice, warm smiles -- but the three little words themselves are avoided.

A person growing up in such a home may unconsciously imitate his parents when he has children, and perpetuate the taboo. Saying "I love you" is felt to be inappropriate or even wrong. Alternatively, he may make a conscious attempt to openly declare his love for his children regularly. I would like to believe that this can work, that people can break away from the legacy of this taboo without fear and without bad consequences for parent or child. To break out of the cycle of constraint, it may be useful to see how the taboo works.

When we say "I love you" to someone, anyone, we are giving them a great gift. If this gift were not routinely given to us, we probably wouldn't pass it along to others. Because we don't have to give it: it is, by definition, freely given. It is something bigger than a birthday present (a well-accepted ritual) or a holiday phone call. It is not a social nicety. It is not supported by custom (although it need not go against custom). It is, importantly, three little words, not ten or fifteen little words (I love you because you're such a nice, cute, little girl, etc.). Because there are only these three, unqualified words, we are saying, "Right here and right now, all of me is giving my love to all of you."

So powerful and potent is the phrase in our culture that it is, sadly, sometimes avoided even in romantic love relationships, most frequently by men. Saying "I love you" involves devotion and commitment. It opens the door to intimacy. We may well ask, "Is it possible that many parents shy away from intimacy with their children?"

My interviews have shown that the parental taboo against saying "I love you" to one's young children carries over to adolescent and adult children. The adult child may then have great difficulty in saying "I love you" to her parents. One of the most strongly held feelings around this issue is embarrassment. There is something invasive, a kind of emotional nakedness, that clings to the phrase "I love you" that causes many adults to avoid it. It may also be that by saying "I love you" people feel themselves at risk of being rebuffed. The other party may not be able to reciprocate. That hurts a lot.

If fear of rebuff is really at the heart of this taboo, then the questions of who says the three little words first and, subsequently, who says them more often, become heartfelt issues. This is more apparent in romantic relationships, in which, typically, each party requires proofs of devotion or at least signs of affection in order to bring out declarations of love from the other. But however different the parent/adult child relationship is from the romantic one, the fear of rebuff, and it's offshoot, pride in not needing anyone's affection, are very much the same in both.

It is no fun to put oneself out to another, whether it be one's children, one's parents, or a casual acquaintance, and discover that they don't respond in kind. One of my respondents told me the following vignette:

She and her father were sitting on the steps of the family's summer cabin in Vermont, watching a beautiful sunset, listening to the country sounds of insects and birds, enjoying the idyllic setting.

Jean remembered this scene with pain and regret twenty years later, this scene where nothing happened -- precisely because nothing happened. She wanted to put her arms around her father and say something along the lines of, "Gee, Dad, I love you." She imagined he felt a similar longing. But both of them let the moment pass.

I suspect that a combination of embarrassment and unwillingness to take that tiny risk of rebuff were what kept the interaction from flowering. It is certainly possible to feel warmth and togetherness in the silence of a sunset. But if a person wishes to say "I love you" and simply cannot say the words, a serious, culturally-based, interpersonal problem is being revealed.

The truth about loving is that it is infinitely replenishable and the more we give, the more we have to give. But many people don't know this. I suspect many feel that if they give love too freely they will be depleted, and they must hold back from explicitly committing themselves to a gift of love by not saying "I love you."

Can we, then, make the leap and say that there is nothing that can equal the regular use of the phrase "I love you" with our children? I cannot, in all fairness, suggest that the total panoply of loving gestures shown by parents to their children does not send the complete message if it lacks frequent use of the spoken phrase. But I am haunted by the way in which the phrase seems to break down barriers to intimacy and break through to something profoundly healing.

You may want to wrestle with the "I love you" issue by answering the questions below. Get personal. Ask yourself how the taboo works, in what ways you partake of it and how you might be able to extricate yourself from it if you feel its constraints.

• Did your parents regularly say "I love you" to you?

• Do you say it to your adult children?

• If not, would it help your relationship if you were to do so?

• Do you feel constrained, embarrassed, or awkward at the thought of saying "I love you" to them?

• If yes, can you think why this might be?

• Do they say it to you?

• If so, does it make you feel good to hear it?

You might be surprised to discover that you would like to say "I love you" to them, and that you would be very pleased to hear your adult children say it to you, if they don't already do so.