I ONCE ASKED my Jewish studies teacher, a mother of eleven, why women were expected to take care of children, and not men. "Women have breasts," she said, enunciating every word slowly while gesturing vaguely at her chest, "that they use to feed the babies. Men don't." In the years since, when I read serious feminist tomes about a woman's role in society or had lengthy discussions with friends about working mothers, or even when I listened to university lecturers and petulant classmates prattle on about "essentialism," the audacious simplicity of Mrs. Cohen's answer always came to mind. Women were biologically geared to nurture babies, and men weren't.

At a screening of the new Kevin Smith film, Jersey Girl, it seemed to me that Hollywood shares this view--the movie industry's new-age feminism notwithstanding. Watching Ollie Trinke (played by Ben Affleck) fumble his way through diaper changes and bottle feeding, I felt a queasy sense of déjà vu at his ineptness. Over the years, we have suffered endless comedies about fish-out-of-water fathers, standard fare like Mr. Mom (1983), where Michael Keaton tried to take over running the household when his wife went to work, or Three Men and a Baby (1987), where three swinging bachelors found their lifestyle stymied by a baby that landed on their doorstep, or last year's Daddy Day Care, in which Eddie Murphy's foolproof plan of opening a day-care center is wrecked by his inability to take care of a gaggle of hyperactive children. For Hollywood, missing mammary glands

But, then again, American movies have always been strangely ambivalent about paternal figures. In his 1996 Life Without Father, family researcher David Popenoe traces the decline in patriarchal authority in America from its apogee in the Puritan era to its deflated status today. Popenoe attributes the decline to a number of factors--such as men's dependency on work outside the home, the rise of individualism, mandatory schooling (which placed another moral authority in the lives of children), the Victorian cult of the mother, and modern feminism--all of which helped transfer household authority from fathers to mothers.

SO PERHAPS it's not surprising that, with few exceptions, Hollywood has portrayed single fathers as parental buffoons kicked into shape by the difficulties of child care. The genre has been around for decades. The Three Stooges poked and bumped their way through baby care in Mutts to You (1938) and Sock-a-Bye Baby (1942); a trio of cowboys on the lam found a baby and meaning in their lives in John Ford's 3 Godfathers (1948); and Bob Hope found himself with child after a baby was abandoned at the United Nations in A Global Affair (1964). Other films too exploited the unnaturalness of male child care, such as Sitting Pretty (1948), about a family that employs a weird male babysitter, or even The Bachelor Father (1931) about a man who decides quite late in life to get to know his children. "What shall we call you?" his children ask him. "'Sir Basil' seems a little distant, but 'Father' is out of the question."