It's one thing to hug your spouse or a close relative, but these days a hug between acquaintances or even strangers sometimes appears to be replacing the old familiar handshake.

The social hug, suggests behavioral therapist Debora Phillips, may have come about "because the extended family is dead" for a great many people in this country.

"People are trying to derive some warmth in other ways from friends, and even new acquaintances," says Phillips, director of the Princeton Center for Behavior Therapy and author of "Sexual Confidence." "They're reaching out for warmth they're not getting from an aunt or their grandparents who are living 3,000 miles away."

That may partly explain why the cocktail party embrace is enjoying such a vogue on the West Coast, particularly in southern California. "there are so many new arrivals there -- so much of a turnover. People have very little sense of solid community."

But, she says, "Some of it is a bit of affectation -- it goes along with the 'Darling' everybody calls everybody." A "mannerism" it may be, but one she finds "nice."

The social hug is also well-established on the East Coast, and that may reflect, she says, the region's large ethnic makeup. Southern Europeans, Latins, Jews "are much freer with physical affections -- even among men in those countries."

But "man-to-man affection," she says, is rapidly shed in this country "because of strict unspoken taboos here." She finds it "beautiful" when men can be comfortably affectionate with one another the way women are.

Among a few college-age men, she is beginning to see this exchange of affection. "Students are expressing envy in seeing women doing this. They're telling me that it feels warm and good to hug another man without sexual overtones."

Learning affection, she says, begins in childhood. "A son whose father stops hugging him at 2 does not usually grow up feeling comfortable touching and hugging. The more affection that we see in our home and we get in our home, the more affection we are able to give and receive comfortably.