Is Social Science an Oxymoron? By William Lama, Ph.D.
Is Social Science an Oxymoron?
By William Lama, Ph.D.
British Sociological Association Is Sociology a Science? (discoversociology.co.uk)
My last essay - “Human Diversity in a Nutshell” - concluded with several bold claims. (1) Like physics, chemistry and biology, psychology has become a “hard” science. (2) Even more remarkable is the assertion that sociology is on the cusp of becoming a science. (3) The key to these momentous advances is DNA and the genetic code that it enables.
Human Diversity in a Nutshell by William Lama, Ph.D. — Palos Verdes Pulse
To these claims I could add the fact that by analysis of an individual’s DNA a scientist is now able to predict the likelihood (probability) of genetic disease, of success in school and even of happiness. Some are frightened by this idea. But wouldn’t you like to know that your baby could be spared a debilitating mental disease with a special diet that does not include breast milk? Some say: So, what? It’s just a probability, that doesn’t make it scientific. Eminent scientists such as Einstein were skeptical of probability in sub-microscopic physics: “God does not play dice with the universe.” His friend Niels Bohr had the perfect answer, "Einstein, stop telling God what to do!" Now we know that Einstein was wrong.
Probability enters the social sciences in the context of “heritability.” For decades after Freud, it was thought that psychological traits were determined by “nurture,” that is by family, friends and environment. Parents were frequently skeptical of this received wisdom. How could it account for one sister who is a princess while the other is a tom-boy? In fact, nurture is only part of the story. This essay focusses on the other part, nature.
Genetics also runs in families. Long before we knew about DNA it was understood that parents and their children as well as brothers and sisters are 50% similar genetically. In his recent book, Blueprint: how DNA makes us who we are, Robert Plomin describes the latest research in psychological heritability.
Plomin begins with a quiz. Cover the last column in this heritability table and guess how likely the following traits are inherited from your parents.
If you have blue eyes there is a 95% chance that one of your parents has blue eyes. Weight is 70% heritable. Blame it on your parents. Psychological traits are on average 50% heritable. If you’re a smart cookie, thank your mom. If you’re a skeptic, your dad may be the problem.
Plomin’s amazing story has two parts: (1) How do we measure heritability? (2) How DNA is the fortuneteller that can predict your odds of a host of physical and psychological traits from birth. The fortuneteller is completely reliable and unbiased – and cheap.
Heritability Experiments
The mountain of data on heritability comes from two types of experiments, one social and the other biological. The social experiments deal with adopted children. Over time do these children become more like their adopted parents (nurture) or are they like their birth parents (nature). Physical traits such as eye color and height are clearly inherited traits. But what about psychological traits such as intelligence and personality? The Colorado Adoption Project (CAP) tracked hundreds of adopted children and tested them at ages seven, twelve and sixteen. Most are still being monitored today in their forties. The results overwhelmingly support the First Law of Behavioral Genetics: psychological traits are substantially inherited; they are in your genes.
The second type of experiment dealt with twins, both fraternal and identical. Since identical twins come from the same egg, they have the same genome (DNA sequence). On the other hand, fraternal twins come from separate eggs and thereby are genetically 50% the same, just like non-twin siblings. If individual differences in a given trait (say weight) are caused entirely by genetics then the correlation of identical twins for that trait would be approaching 100%. For fraternal twins the correlation would be 50%. Twins are a gift to science. Measured heritability data come from an enormous study of twins in Britain including 16,000 one year old twins. The Twins Early Development Study (TEDS) began with twins born in 1994 and has continued over 25 years. The data set consists of over 55 million items collected from twins, parents and teachers. Once again, the data support the CAPS finding that psychological traits are substantially inherited.
From the table of data shown above we see that the heritability of weight is 70%. Weighty parents generally have heavy kids, no matter whether they live with their birth parents or with adoptive parents. The heritability of intelligence is 50%. Brainy parents are likely to have brainy kids. But it’s not guaranteed. In grad school I had a physics professor with eight children. All had higher than average intelligence. But he was sure that sooner or later they would have a genius. I’m not sure what his wife thought of this strategy.
Heritability Science
The TEDS study has obtained DNA from over 18,000 twins, and that is where we will look for the root cause of heritability. Recall that the DNA contained in the single cell we inherit from our parents is replicated in every body cell as we grow. Furthermore, human DNA is 99% identical in all humans. Of the three billion base-pairs in the human genome only 1% or thirty million define our individuality. For obscure reasons scientists call the differences Single Nucleotide Polymorphisms (or SNPs, pronounced “snips”). An SNP can make a big difference. For example, chromosome 16 has 90 million rungs (base pairs) in its DNA helix. At rung number 53,767, 042 within a gene called FTO is an SNP where a mutation changed a T to an A in one individual. Today 60% of humans have the AT pair while 40% have the mutant AA. This SNP accounts for a weight gain in those unlucky individuals who have the mutant “FaTsO” gene. Another single gene disorder is phenylketonuria (PKU) which, untreated, causes severe intellectual disability. However, by screening newborn’s DNA for the PKU gene this bullet can be dodged by a low phenylalanine diet not including breast milk. For these babies and their parents this recent development is a miracle.
But these are rare cases. Most human traits, especially psychological traits, are a consequence of multiple SNPs. For example, consider intelligence – the ability to learn, reason and solve problems. Decades of research involving twins and adoptees has demonstrated that intelligence is heritable. Over 50% of the person-to person-variability is inherited. Genetic research has shown that even the most strongly associated SNPs explain less than 1% of the human-to-human variance. The heritability of intelligence is caused by a very large number of DNA SNPs of small effect. The latest polygenic research is able to account for 20% of the 50% variance of intelligence determined by twin studies. It took a technology breakthrough that enabled whole genome mapping of tens of thousands of individuals to acquire enough data to reach the 20% level, but the data generation is growing exponentially.
Heritability Technology
The first human genome map was completed in 2004. The Human Genome Project involved the efforts of hundreds of scientists for over a decade, at a cost of $3 billion.
Human Genome Project - Wikipedia
Creative biology and digital technology driven by Moore’s Law has reduced the cost of a genome sequence down to about $100. The direct-to-consumer genomics company 23andMe has over 2 million customers and 80% have agreed to allow their DNA to be used for medical research. DNA Genetic Testing & Analysis - 23andMe
And it’s even possible to have your DNA sequenced for free. This Startup Will Sequence Your Genome for Free — But There’s a Catch | Digital Trends
The technology breakthrough is the Gene Chip, an analytical tool that analyzes many DNA fragments densely placed on a glass substrate for detection of changes in expression of genes. These DNA microarrays enable exhaustive analysis of several hundred thousand genes with a small amount of sample and in a relatively short time.
Global DNA and Gene Chip (Microarrays) Market Size, Share, (openpr.com)
Whole genome sequences have already been obtained for several hundred thousand individuals. It’s expected that in the next few years a billion people will have their DNA sequenced and linked to electronic medical records.
The Question
So, is social science real or an oxymoron? Auguste Comte (1798-1857) was the first to develop the concept of "sociology" as a search for "invariant laws of the natural and social world." Comte argued that “sociology must have a scientific base and be objective.” That’s not a bad starting point. For it to be a (hard) science sociology must also be able to make predictions that are testable and accurate. I’d say that sociology is on the cusp of becoming a science due to the remarkable predictive power of DNA and the science and technology of polygenic heritability. It’s a Brave New World that could be a boon to humankind.
Dr. William Lama has a PhD in physics from the University of Rochester. Taught physics in college and worked at Xerox as a principle scientist and engineering manager. Upon retiring, joined the PVIC docents; served on the board of the RPV Council of Home Owners Associations; served as a PV Library trustee for eight years; served on the PV school district Measure M oversight committee; was president of the Malaga Cove Homeowner's Association. Writes about science, technology and politics, mostly for his friends.
email: wlama2605@gmail.com