8

Perhaps more importantly, the fact that Terry chose to focus on two physical attributes — height and eye color — points up a common mindset which attributes "humanity" or "personhood" to anything that looks to us like a human baby.

As a species, humans have inherited a genetic tendency to respond favorably to certain physical characteristics that human babies possess. This reaction helped to ensure preservation of species, back when it was a little more in doubt than it is today. But it is interesting to note that we respond to the same cues in other, non-human species as well. The so-called "toy" breeds of dogs, such as the Pekingese, have been shaped to serve as sort of child substitutes. Selective breeding has ensured that they never grow any bigger than a five-month-old infant. Their flattened faces "approximate the profile of the human baby" and they have "the huge, bulging eyes so typical of the human newborn." ¹⁷

Likewise, many people find young chimpanzees cute and appealing, precisely because they look so human. Older chimps, with the receding forehead and jutting jaw that develop with age, are more likely characterized as brutish or frightening.

It is no wonder, then, that adults respond empathetically to pictures of aborted fetuses where tiny fingers are clearly visible, or where the face has characteristically human features. Facial features are distinctly recognizable at fourteen weeks. By the fourth month, you can tell the face of one fetus from that of another. And at a mere eight weeks, hands and feet are distinguishable from each other and have humanlike characteristics.

On the other hand, a three-week-old embryo is approximately two millimeters long and "looks a little like a segmented worm." A four-week-old embryo is still mostly tail; it has gills like a fish and "looks something like a newt or tadpole." At six weeks, it is approximately half an inch long and has a reptilian face with "connected slits where the mouth and nose eventually will be. By the end of the seventh week the tail is almost gone, and ... the face is mammalian but somewhat piglike. By the end of the eighth week, the face resembles that of a primate but is still not quite human." ¹⁹ In short, for the first two months the embryo looks like virtually everything except the human it may eventually become.

(At this point I must digress for a moment, as the dating methods for pregnancies and embryos are different and easily lead to confusion. Gynecologists and obstetricians, for the sake of convenience, measure the length of a pregnancy from the start of the woman's last menstrual period. The age of an embryo or fetus, however, is typically measured from conception, which occurs approximately two weeks later. This dichotomy means that a fetus which is twelve weeks menstrual age is actually only ten weeks from fertilization. ¹³ This is an important point to remember, since a woman who is, say, eight weeks pregnant, would only be aborting a six-week fetus.)

If a recognizably primate face, or fingers, or the ability to use tools and language defined a human being, then chimpanzees and gorillas would easily qualify. To deliberately kill a human being is murder. Yet to deliberately kill a chimpanzee — biologically, our closest relative, sharing 99% of our genes — is not.

next