13-9 What is included in the biopsychosocial approach to development?

“There are trivial truths and great truths,” reflected the physicist Niels Bohr on the paradoxes of science. “The opposite of a trivial truth is plainly false. The opposite of a great truth is also true.” Our ancestral history helped form us as a species. Where there is variation, natural selection, and heredity, there will be evolution. The unique gene combination created when our mother’s egg engulfed our father’s sperm predisposed both our shared humanity and our individual differences. Our genes form us. This is a great truth about human nature.

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But our experiences also shape us. Our families and peer relationships teach us how to think and act. Differences initiated by our nature may be amplified by our nurture. If their genes and hormones predispose males to be more physically aggressive than females, culture can amplify this gender difference through norms that shower benefits on macho men and gentle women. If men are encouraged toward roles that demand physical power, and women toward more nurturing roles, each may act accordingly. Roles remake their players. Presidents in time become more presidential, servants more servile. Gender roles similarly shape us.

In many modern cultures, gender roles are merging. Brute strength is becoming increasingly less important for power and status (think Mark Zuckerberg and Hillary Clinton). From 1960 into the next century, women soared from 6 percent to nearly 50 percent of U.S. medical school graduates (AAMC, 2012). In the mid-1960s, U.S. married women devoted seven times as many hours to housework as did their husbands; by 2003 this gap had shrunk to twice as many (Bianchi et al., 2000, 2006). Such swift changes signal that biology does not fix gender roles.

If nature and nurture jointly form us, are we “nothing but” the product of nature and nurture? Are we rigidly determined?

We are the product of nature and nurture, but we are also an open system (FIGURE 13.7). Genes are all-pervasive but not all-powerful. People may reject their evolutionary role as transmitters of genes and choose not to reproduce. Culture, too, is all-pervasive but not all-powerful. People may defy peer pressures and do the opposite of the expected.

We can’t excuse our failings by blaming them solely on bad genes or bad influences. In reality, we are both the creatures and the creators of our worlds. So many things about us—including our gender identities and our mating behaviors—are the products of our genes and environments. Yet the future-shaping stream of causation runs through our present choices. Our decisions today design our environments tomorrow. The human environment is not like the weather—something that just happens randomly. We are its architects. Our hopes, goals, and expectations influence our future. And that is what enables cultures to vary and to change. Mind matters.

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We know from our correspondence and from surveys that some readers feel troubled by the naturalism and evolutionism of contemporary science. (Readers from other nations bear with us, but in the United States there is a wide gulf between scientific and lay thinking about evolution.) “The idea that human minds are the product of evolution is … unassailable fact,” declared a 2007 editorial in Nature, a leading science journal. That sentiment concurs with a 2006 statement of “evidence-based facts” about evolution jointly issued by the national science academies of 66 nations (IAP, 2006). In The Language of God, Human Genome Project director Francis Collins (2006, pp. 141, 146), a self-described evangelical Christian, compiled the “utterly compelling” evidence that led him to conclude that Darwin’s big idea is “unquestionably correct.” Yet Gallup pollsters have reported that half of U.S. adults do not believe in evolution’s role in “how human beings came to exist on Earth” (Newport, 2007). Many of those who dispute the scientific story worry that a science of behavior (and evolutionary science in particular) will destroy our sense of the beauty, mystery, and spiritual significance of the human creature. For those concerned, we offer some reassuring thoughts.

When Isaac Newton explained the rainbow in terms of light of differing wavelengths, the British poet John Keats feared that Newton had destroyed the rainbow’s mysterious beauty. Yet, as Richard Dawkins (1998) noted in Unweaving the Rainbow, Newton’s analysis led to an even deeper mystery—Einstein’s theory of special relativity. Moreover, nothing about Newton’s optics need diminish our appreciation for the dramatic elegance of a rainbow arching across a brightening sky.

When Galileo assembled evidence that the Earth revolved around the Sun, not vice versa, he did not offer irrefutable proof for his theory. Rather, he offered a coherent explanation for a variety of observations, such as the changing shadows cast by the Moon’s mountains. His explanation eventually won the day because it described and explained things in a way that made sense, that hung together. Darwin’s theory of evolution likewise is a coherent view of natural history. It offers an organizing principle that unifies various observations.

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Collins is not the only person of faith to find the scientific idea of human origins congenial with his spirituality. In the fifth century, St. Augustine (quoted by Wilford, 1999) wrote, “The universe was brought into being in a less than fully formed state, but was gifted with the capacity to transform itself from unformed matter into a truly marvelous array of structures and life forms.” Some 1600 years later, Pope John Paul II in 1996 welcomed a science-religion dialogue, finding it noteworthy that evolutionary theory “has been progressively accepted by researchers, following a series of discoveries in various fields of knowledge.”

Meanwhile, many people of science are awestruck at the emerging understanding of the universe and the human creature. It boggles the mind—the entire universe popping out of a point some 14 billion years ago, and instantly inflating to cosmological size. Had the energy of this Big Bang been the tiniest bit less, the universe would have collapsed back on itself. Had it been the tiniest bit more, the result would have been a soup too thin to support life. Astronomer Sir Martin Rees has described Just Six Numbers (1999), any one of which, if changed ever so slightly, would produce a cosmos in which life could not exist. Had gravity been a tad stronger or weaker, or had the weight of a carbon proton been a wee bit different, our universe just wouldn’t have worked.

What caused this almost-too-good-to-be-true, finely tuned universe? Why is there something rather than nothing? How did it come to be, in the words of Harvard-Smithsonian astrophysicist Owen Gingerich (1999), “so extraordinarily right, that it seemed the universe had been expressly designed to produce intelligent, sentient beings”? Is there a benevolent superintelligence behind it all? Have there instead been an infinite number of universes born and we just happen to be the lucky inhabitants of one that, by chance, was exquisitely fine-tuned to give birth to us? Or does that idea violate Occam’s razor, the principle that we should prefer the simplest of competing explanations? On such matters, a humble, awed, scientific silence is appropriate, suggested philosopher Ludwig Wittgenstein: “Whereof one cannot speak, thereof one must be silent” (1922, p. 189).

Rather than fearing science, we can welcome its enlarging our understanding and awakening our sense of awe. In The Fragile Species, Lewis Thomas (1992) described his utter amazement that the Earth in time gave rise to bacteria and eventually to Bach’s Mass in B Minor. In a short 4 billion years, life on Earth has come from nothing to structures as complex as a 6-billion-unit strand of DNA and the incomprehensible intricacy of the human brain. Atoms no different from those in a rock somehow formed dynamic entities that became conscious. Nature, said cosmologist Paul Davies (2007), seems cunningly and ingeniously devised to produce extraordinary, self-replicating, information-processing systems—us. Although we appear to have been created from dust, over eons of time, the end result is a priceless creature, one rich with potential beyond our imagining.

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