When Does Personhood Begin?

Howard A. Schneiderman Professor of Biology Scott Gilbert admits he can't answer the question he poses at the start of his popular talk. However, he adds with "absolute certainty" that there is also "no consensus among scientists." Gilbert, who teaches embryology and developmental genetics, is frequently invited to lecture on this subject and has given this talk to diverse audiences from around the country to the Vatican. This lecture was recorded at the annual conference sponsored by the Association of Reproductive Health Professionals, Planned Parenthood of America, and the Society of Family Planning. Gilbert is the author of the best-selling textbook Developmental Biology, now in its eighth edition. He is also the co-author a volume on bioethics (written with two of his former students, Anna Tyler '03 and Emily Zackin '02) and of the recent book Ecological Developmental Biology (2009), which has received outstanding reviews in Nature, Science, and the American Scientist.


Audio Transcript

Scott Gilbert: Thank you very much, and when I say that it is a great honor to give the Burnhill Lecture, I do not mean it lightly. I'm not an obstetrician/gynecologist, but I've been married to one for over 35 years. I met [Ann Rario 00:00:31], who is here at the meeting, when she was an undergraduate campaigning for the rights of unmarried women to be given access to birth control information and condoms by the college physician. Indeed, the topics of this meeting have been our dinner table conversations throughout our adult life, much to the consternation of our children. Like many of you, she has been working in a poorly funded clinic trying to provide dignified context for providing accurate and useful family planning information, so I am greatly honored that you would ask me to speak here today. I also consider this probably the anti-Vatican, a much more friendly audience. The people invited me to the Vatican were the Legionaries of Christ. I think I was the promised diversity on their grant proposal.

Well, when does human personhood begin has now a new urgency in the context of the revised personhood movement, and I hope that public education on the scientific notions of personhood may finally quash the idea that a zygote is a person. It's actually a great opportunity since the case for zygote rights is very weak. I have no interest to disclose, learning objectives. I've been in your book. I'll just go here.

I really can't tell you when personhood begins, but I can say with absolute certainty that there's no consensus among scientists. Some scientists will say it begins at fertilization, where the zygote gets a new genome, where the sperm and egg combine, their nuclear materials, which actually is a long process ending with a two cell stage. Some scientists will say it's at implantation, where you get a pregnancy. Other scientists will say it's at day 14, gastrulation, where the embryo becomes an individual, where you can no longer form twins and triplets, so that you have one embryo giving rise to, at best, only one adult. Some scientists will say it's at week 24 to 28 when you see the beginnings of the human specific electroencephalogram, and saying if we're willing to say that death is the loss of the EEG, perhaps personhood is the acquisition of the EEG. Still others say it's at birth or during the perinatal period where a successful birth is possible.

One of the questions one has to ask is why does the public even think that life can begin at fertilization. Why did I go into and got into this whole question when I saw a religious action notice on a bulletin board at the college that said, "Philosophers and theologians have argued for centuries as to when personhood begins, but scientists know when it begins. It begins at fertilization." Why do people think this? I think that there's social information, or misinformation, that's being given, and I call this the Syllabus of Errors.

The first one is that the instructions for development and heredity are all in the fertilized egg. The second, that the implanted embryo is safe within the womb. The third, that there is a moment, a specific moment, of fertilization where a passive egg meets an active sperm, think about the Look Who's Talking movies. Fourth, there's a consensus among scientists that this is where personhood begins.

Now the first error is that the instructions for development and inheritance are all in the fertilized eggs, and we see this going back to Paul Ramsey in 1970 where he says that, "genetics teaches that we were from the very beginning what we essentially are in every cell and in every human attribute." Well, this was 1970. In 2005, and I recently accessed, still there, from Stand Up Girl, which is a website which poses as a cool teen site. It's actually sponsored by the Oregon Right to Life Society. It says, "Even more amazingly, intelligence and personality - the way you look and feel - were already in place in your genetic code at the moment of conception. You were essentially and uniquely you." You are you at conception. You are you. You get this DNA at conception. Well, so what?

Well, popular culture promotes the fallacy of sacred DNA, and this was from research done by Dorothy Nelkin and Susan Lindee. It's published in a book called The DNA Mystique, and they looked at the important literature. They didn't look at Nature, science proceedings, National Academy of Sciences. They looked in Cosmopolitan, Vogue, Redbook, Newsweek. They asked the question, how is DNA being represented? They found that it was being represented as the secular equivalent of soul. First it was that which is your essence, as that Stand Up Girl said. It is that which your determines your behaviors, as Ramsey and Stand Up Girl said. It's that from which you an be resurrected after death, a la Jurassic Park.

We are uniquely who we are at conception. The DNA is sacred, and it's so pervasive in our culture that you'd be amazed. If I were to ask you do cars have DNA? You'd probably say no. But you'd be wrong. DNA is become the metaphor for our essence, for that which makes you you, so even cars, when they do their advertising, a Sterling's remarkably handling is "in its genes", a Subaru is a "genetic superstar", Toyota "has a great set of genes", and "The new Nissan designed DNA is evident". DNA is become essence. Here's the most recent one. "Same DNA. Smaller chromosomes." Look, Hummer is not going to put this ad on the back of Newsweek if it hasn't been tested.

The culture of America believes that DNA is our essence. We get a Finish newsletter at our house, and in one of the articles it says, "The sauna is in the DNA of every Finn." No, the sauna is not in the DNA of every Finn. Can't find it there. Our antibodies won't see it. It's in the soul of every Finn, and this notion of DNA is soul just is rampant through our literature, but we know scientifically this is not so.

Doctor Jones and others talked yesterday about epigenetics. Here we see two genetically identical mice. They do not look genetically identical. Their mothers were given different diets. The different diets actually activated and suppressed different genes, so one is obese and golden, the other is sleek and brown, so the genes are not determining their obesity in this case. The genes are not determining their color. It's the environment, the maternal diet that's doing this.

I'm not going to go into this slide, but maternal care can activate or repress gene expression in rats. Here we see the glucocorticoid receptor in the brain of rats, and depending on whether the rats got maternal care during the first seven days of postnatal life, you either activate or un-activate this particular gene. In both cases, this is due to DNA methylation, this epigenetic phenomena.

We even get a separate inheritance. We get bacteria. As we go through the reproductive tract of the female, we get new bacteria. That bacteria colonizes our gut. Our gut expects it. We get variation. We get finished by the bacteria that we inherit, often through birth.

So the new syllabus would say that we are not determined to be essentially who or what we are at fertilization. Many of our fundamental bodily behavioral characters are not determined by genes, but by the environment.

The second error, and this is a quotation from C. Ward Kischer, who is the chairman of the American Advisory Council for Bioethics, a Catholic organization, says, "From the first moment of conception, human development is a fait accompli under conditions which we have come to understand and embrace as NORMAL." His emphasis. I wish this were true, but certainly obstetricians and gynecologists know all too well that the fetus is not safe, the embryo is not safe within the womb, and that most conceptions, most fertilization events do not come to term as babies, and Michael Sandel when he was brought before the President's Commission on Bioethics said, "If the embryo lost that accompanies natural procreation were the moral equivalent of infant death," in other words, if the zygote is a person, "then pregnancy would have to be regarded as a public health crisis of epidemic proportions: Alleviating natural embryo loss would be a more urgent moral cause than abortion, in vitro fertilization, and stem cell research combined."

We know drugs, chemical teratogens, the endocrine disruptors, bisphenol A causes myotic abnormalities in the embryonic mice. BPA exposure in utero predisposes rat mammary glands to have cancers later in life. These are important things. The fetus is not safe. It doesn't come to term normally. Matter of fact, a majority of conceptions do not. Current technological society's increasing the risk that babies will with be born with anomalies, fertility problems, and susceptibilities to disease, as Doctor Jones mentioned yesterday. Moreover, these anomalies and disease susceptibilities we now know can be transferred through the DNA, through these DNA methylation changes, these epigenetic changes to children and grandchildren.

Now, this is an obvious place where science and religion can become allies. I was just thinking. Imagine the newspaper headlines that the Planned Parenthood and League of Bishops announce that they're campaigning against fetotoxic chemicals. That might actually mean something. When religion and science are separated, economics wins, but when they're together I think that there's very little that can stand between them.

Error three I'll just go into very quickly. That there is a moment of fertilization where a passive egg meets the active sperm, and here we see the sperm race shown in a children's book, and I can show you a whole other lecture of sperm race and how the notion is that the oviduct is a passive conduit through which sperm race, and that the victor fertilizes the egg, and that the reproductive tract doesn't do anything. It's a wonderful myth. It's a hero myth. We are not the progeny of some wimpy sperm. We are the progeny of heroes. You know, this is like the Aeneid. This is a founding myth. But it's not true.

As [Bayard's 00:12:55] story says, that the first sperm get to the egg in about 30 minutes, and even the most Olympian of sperm can't do this on their own, and when they get to the egg they can't fertilize it because they haven't undergone capacitation. The sperm finish their development in the female reproductive tract, in the isthmus right before the ampulla of the oviduct. The oviduct cells bind the sperm and change their cell membranes so that they can reach the zona pellucida and fertilize the egg. Also, the pronuclear movements that occur during human fertilization take about 20 to 24 hours. It's not a moment of fertilization. It's quite an event.

So the new syllabus is that fertilization is not immediate. Coitus does not mean impregnation. That word, impregnation, should be banned. No, again, those people who are involved in trying to get Plan B into the pharmacies know this, that the notion of "Oh, you had intercourse. You're pregnant," is not correct. It's not immediate. As one fertilization researcher says, "Fertilization does not occur in a moment of passion. It occurs five days later at the laundromat." Okay. Okay.

Error four, that there's a consensus among scientists as to when personhood begins. Here we have "Every human embryologist worldwide, states that the life of new individual human being begins at fertilization." Well, we know that this scientifically is really challenged, that as I mentioned before, there are at least, at least, five places, sometimes people would say six or seven, but these are the ones I'll talk about: fertilization, gastrulation, EEG pattern, and the perinatal period.

Position one: Personhood begins at fertilization. Here's where the geneticists say life begins. A unique genome is made and the conditions exist to generate a new person. So, when asked in Human Life Review in the spring of 2002, "At what point does individuation take place?" Doctor Jerome Lejeune, very well known geneticist, person who really identified Down Syndrome as a genetic chromosomal disease, said, "Oh. That takes place fecundation, at fertilization, at conception. Because it just tells us that the constitution of this person is unique to this person." Well, we know that this notion, "because it tells us that the constitution of this person is unique to this person" is wrong because of twinning, and here's where the second position takes place, that human personhood begins at gastrulation.

Now, gastrulation is the time of embryology where the embryo cells start moving and acquire new neighbors and become an individual. It's when the cells are told what they're going to become. Gastrulation, gut formation what it literally means, is the cells of the gut are told, "You're going to be gut cells, and not nerve cells. You're not going to become skin cells." And so here, you have the end of the ability to form twins or triplets, quadruplets. This is an important point, and indeed, this notion of day 14, gastrulation, being the beginning of personhood is the law in Great Britain, Singapore, numerous places throughout the world, and it allows people to work on stem cells, because that occurs before day 14.

Now, Renfree, an embryologist says, "Assuming that monozygotic twins have separate souls," okay. He's going to that notion of ensoulment now. "Assuming that monozygotic twins have separate souls, it follows that ensoulment, whatever it must be, must occur after cleavage, at least 12 days after conception." So that as long as you still have cleavage and the ability to form more embryos with the same genome, they can't be ensouled, because they're different people. Bioethicist Robert Green says, "But twinning and fusion events suggest that, even well after the formation of the zygote, biological individuality is not firmly established. Only at gastrulation can we say that the lengthy process of individuation is complete." So that you're not an individual person until day 14, gastrulation. And of course, here's monozygotic twinning. I don't have to talk to you about this here, but you can get monozygotic twinning fairly late, even twins forming in the same amnion.

You can also, this is the reverse of twinning. You can get chimeras, and this was first shown in mice in the 1960s where two mouse embryos, one from white furred parents and one from black furred parents where combined together. Their zona pellucida was gotten rid of. They were put together so that the embryos formed a composite blastocyst. That blastocyst was then transferred into a foster mother, into the uterus, and what resulted were stripped mice. Not two mice. Not a two headed monster or a two tailed monster, but one individual mouse. This mouse had normal behavior. It mated, it did all sorts of things. Hundreds of these mice have been made, and those of you who saw CSI know that there are human chimeras. That was one of the things. The sperm sample didn't match the blood sample. Yeah, that's why. As I was writing a lecture, and my son was saying, "What's going on?" I said, "He's a chimera." [inaudible 00:19:04] said, "What's that?" "They'll explain." Yeah. So, chimeras, this actually happens. It's incredibly rare, it's reportable, but they do happen, and you don't get a two headed individual. You get one person who acts like one person.

Position three is that personhood begins when the fetus acquires the human specific electroencephalogram pattern. 1992, Morowitz and Trefil, two Yale biologists physicians said, "In our usage, we say that our species acquired humanness when the enlarged cortex develops, and the individual fetus acquires humanness when the cortex begins to function." So when does it begin to function? New data suggests that quote, "We are able to identify specific patterns and track changes in the fetal brain activity starting at 28 weeks of gestation." Even then, those are sleep EEGs. There's no indication of fetal awareness. So if loss of EEG pattern is considered human death, even though the heart is beating, cells are aspiring, et cetera, then acquisition of the EEG could be considered human life, when you receive a personhood.

There's all sorts of corollary arguments to this, and this one is important, because you'll see in the literature of the personhood movement that once are you a human, you are a person. Well, corpses are not considered persons, even though they are considered humans. Neither is counted in a census, neither can inherit, neither has moral agency, but they're both given respect. You don't eat a corpse if it is human. Even though it's considered human, it's not considered a person. There's the argument of respect, that they're treated with respect because of they're human condition, even if not given the rights of personhood.

Position four, that personhood begins at birth. This is legal personhood. The time of one's identity. Again, this is very important because this is usually when the fetus enters society. It becomes a physiologically independent who, as compared to a what. It has social agency, and the notion that birth is just going from one room to another is really something that obstetricians know is wrong. That birth is not merely such a move, it's a passage, and a very perilous discontinuity between fetal and new born life. The lungs have to be able to function, the first breath changes heart anatomy, the first breath, which according to Hebrew tradition is when the nephesh, the soul, enters the body, changes blood circulation within the heart and within the body, and of course, the head has to get through the birth canal. This is not an easy transition.

Now, there's a position five, which is the gradual acquisition of personhood, and in the scientific literature, it was put forth by very well known biologist Theodosius Dobzhansky, who said, "The wish felt by many people to pinpoint such a stage," when personhood begins, "probably stems from the belief that a soul, conceived as a preternatural entity, descends upon a formally soulless living stuff, and suddenly transforms the latter into human estate. I hope that modern theologians," he's talking 1976, "can accept the idea that the transformation is not sudden, but gradual." And interesting, that was the point of many Roman Catholic theologians, including Albertus Magnus and Thomas Aquinas, that the transformation is not sudden, but gradual. You got different souls when the anatomy changed.

So there's no consensus among scientists as to when human personhood begins. Personhood can begin at fertilization, individual genotype with cells capable of developing into humans, gastrulation, when you have human individuals, when you have animal specific movement, and can no longer form twins, getting the EEG, the electroencephalogram, which has the symmetry as death as its loss, and the perinatal period, the ability to breath, legal personhood, social agency, and distinctness from the mother, and then the gradual humanization during embryogenesis.

Now one thing I want to talk about, the personhood movement and its dangers, is that the equation works both ways. When we're talking about zygote rights, when we're talking about the zygote as a person, we're also talking about the person as a zygote. If the zygote or the blastocyst is a person, can the person be treated as a zygote or a blastocyst? Is a zygote a who or a what? If it is a what, then the dignity of the newborn or the adult is enormously diminished, and the parable of the man walking into a burning clinic and sees on the clinic floor a young woman and a canister, and the canister says "1000 embryos", which do you rescue? Who do you rescue? This is basically the question, do you really think that a zygote or blastocyst is the equivalent of a human person? I think it really, the question really says it well, what or who do you rescue? The zygotes, the blastocysts are still what.

There's actually an interesting Biblical break on equating persons with human embryos. The syllogism goes like this, Genesis 9:16 says that those who kill the image of God must themselves be killed. Exodus 21:22, which is in a passage explicitly about what killings are murder and what killings are not murder, says that if a man causes a woman to miscarry, he is not killed, but he has to pay a fine to the woman's family, determined by the court. So, the fetus then does not have the image of God. According to these passages, the image of God, personhood, is obtained at birth. It is a, literally, a birthright.

Just to end, there is no consensus among scientists as when personhood begins. Matter of fact, the notion of fertilization is a rather weak statement because of the ability of the same genetic material to form twins and triplets. Probably no one realizes what an incredible event human personhood is than the embryologist and the obstetrician/gynecologists. Embryologist Jean Rostand wrote, "Quite a profession this is - this daily inhalation of wonder." I think that this is in some ways, it could be a wonderful teaching moment, to teach the public about what its assumptions are, what its misconceptions are about conception, and I have here, and it's on the handout, some references. These are two papers that I've done. One is a bioethics book, one is a paper on personhood. You should be able to get the chapter on personhood from the Sinauer website. Also, for those interested in epigenetics and epigenetics teratology in medicine, I just co-authored a book with David Eple called Evolutionary Developmental Biology: The Synthesis of Epigenetics Medicine in Evolution, and for those of you interested in that aspect, the chapters there should be interesting. Thank you very much.