"20 billion:  Number of letters, packages and cards the U.S. Postal Service expects to deliver between Thanksgiving and Christmas this year. The busiest mailing day this year is expected to be Dec. 18, with more than twice as many cards and letters being processed as the average on any given day.

About 12 million:  Number of packages delivered by the U.S. Postal Service every day through Christmas Eve. The busiest delivery day: Dec. 20.

"At Christmas, not only Christians but all the world thinks of babies - babies today, and The Baby then, Jesus Christ. As Wesley, the greatest poet of Christmas since he was of all hymn-writers most alive to the divine assumption of human nature, sang:

Our God contracted to a span
Incomprehensibly made Man.

He was "made Man" as a baby; to be precise, he was manifest as a baby having been miraculously conceived in his virgin mother's womb, in a central Christian doctrine of telling relevance to contemporary bioethics. Human nature, in its indivisible and ineffable dignity and from its first beginnings, bore the weight of the Second Person of the Trinity. Any lingering doubts that humankind may have had as to human worth were vanquished with one stroke of the divine pen as 'the Word became flesh.'"

As a disproportionate amount of research on teenage sexual behavior focuses on disadvantaged youth-particularly those living in broken families or with single parents-perceptions of promiscuity among teens in general are often exaggerated. Yet a study by Mark Regnerus, a sociologist at the University of Texas, provides a sharper picture of high school students from standard, intact families, identifying clues that might help parents keep their teenagers on the straight and narrow.

Among his chief findings: Teen daughters of married parents are more likely to retain their virginity if they enjoy close relationships with their fathers (p<.01 in the first statistical model; p<.10 in the second), a pattern that was not replicated with sons or in connection with the quality of relationships with mothers. The finding comes from regression analysis of data from the National Longitudinal Study of Adolescent Health, where Regnerus used a subsample of almost 2,400 respondents (ages 15 and above) living in biologically intact families who were interviewed initially in 1995 and a year later. In this sample, while 63 percent of boys and 66 of girls were virgins in the first wave, those proportions declined to 49 percent and 51 percent, respectively, by the second wave.

While these percentages might still seem high given the sample, the second statistical model accounts for other factors that also increased the odds that his virgin teens remained so between the two interviews. For both boys and girls, not dating or dating infrequently, as well as anticipating guilt if they engaged in premarital sex, were each strongly associated with keeping one's virginity (p<.001 for all four coefficients). For girls (but not boys), attending church regularly and perceiving that their parents disapprove of premarital relations also increased the odds of remaining chaste (p<.05 for both).

While dads often feel off balance when their little girls become teenagers, these findings demonstrate that involved dads make a difference, especially when they connect to their daughters, attend church with them weekly, and keep their dating to a minimum.