BG Outcomes & Edna Millay

Behavior Genetics: Outcomes & Edna St. Vincent Millay
James Brody, Ph.D.
Taken from a chapter, "We're all twins," revised 12/25/02 for this posting on BoL.
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After hearing my lecture in 1998, "Here comes granddad again," Robert Wright asked John Pearce, "Is this true?"
Pearce, with a smile and a shrug: "It's all anecdotal."

"Forget 'As the twig is bent'; think 'Omigod, I'm turning into my parents!'" Steve Pinker (2002, p. 375).

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Popular and scientific media discuss the striking similarities between the members of identical twins. Reared apart or together, it makes little difference. (See HO: We're All Twins.) We've all seen these effects, the media and research press tell their story. Science and publicity have not, however, described plausible mechanisms. How do we get to two adult males who wear shirts with shoulder flaps and 4 buttoned pockets, each filled with pens. Similar, genetically influenced receptor biases might offer an explanation: in rich environments, similar genes will express similar traits because of similarity in preferences that are largely innate.(1)
The Big 5 (Five Factor Model): extraversion, emotionality, agreeableness, conscientiousness, and openness often appear in studies of personality and typically demonstrate heritability between 0.30-0.50.(2) Pinker (2002), p. 50, comments: "The unfortunate wretch who is introverted, neurotic, narrow, selfish, and undependable is probably that way in part because of his genes..."

Identical Twins vs. Fraternal Twins
Bouchard, et al. (1990) assessed identical twins reared apart (31-56 pairs, depending on the measure) and identical twins reared together (42-274 pairs, also depending on the measure). They measured height (rxy = 0.86) and weight (0.73), and the number of finger ridges (0.97). Bouchard's group also measured brain alpha activity (0.80), systolic blood pressure (0.64), heart rate (0.49), and electrodermal response amplitude (0.82 for males, 0.30 for females) and speed of habituation (0.43). They assessed information processing (0.56 for speed of response, 0.20 for acquisition speed, 0.36 for acquisition of spatial processing), WAIS I.Q. verbal (0.64), performance (0.71), and full scale (0.69), special mental abilities (0.45 Hawaii-battery) and personality (Multidimensional Personality Questionnaire, 0.50, and the California Psychological Inventory, 0.48). The Strong Campbell Interest Inventory (0.39), the Jackson Vocational Interest Survey (0.40), and the Jackson Vocational Interest Survey (0.43) were administered. They compared religiosity on 2 measures (mean 0.49), the mean of 14 items that related to non religious social attitudes (0.34), and responses to a traditionalism scale (0.53). The ratio of heritabilities for twins reared together and twins reared apart ranged between 0.90 and 1.21 for 16 of 22 measures taken!
Rearing conditions had no effect on most of the measures taken and only a small to moderate effect on female electrodermal response (0.555), information processing speed (0.767), full scale WAIS IQ (0.784), verbal WAIS IQ (0.727), the mean of 23 Strong Campbell Interest Inventory scales (0.813), and the mean of 17 Minnesota Occupational Interest scales (0.816).

According to Plomin (1994, p. 3) the correlations in behavior between MZ twins are some of the largest in the behavioral sciences and testify to the resilience and diversity of genetic influence. (3) Some of the correlations between genes and human behavior include memories of parental warmth (Rowe, 1981, 1983), children's perceptions of their parents (6 studies), closeness to siblings (Baker and Daniels, 1990), peer choice (Baker and Daniels, 1990), friend and teacher attributes (Manke et al., (1993); perception of social support (Bergeman et al.,1990; Kessler et al., 1992, 1994), life events such as crises in marriage, vocations, finances, and health (REF); accidents by age 3 (Phillips and Matheny, 1993), television viewing (Plomin et al., 1990), drug exposure (Tsuang et al., 1992; 2001), child rearing (Perusse et al., 1994), Over Anxious Disorder but not Separation Anxiety (Topolski et al., 1997), socioeconomic status, and education (Plomin, Lichtenstein, et al., 1990). Plomin and Lichtenstein (1990) found a greater heritability for individual crises if the individual was in control of the situation.

MZ make more similar errors on tests than DZ and are more likely to be accused of cheating from each other (Segal, 1999) and MZ are more similar in verbal and nonverbal items on intelligence and achievement tests than are DZ. MZ are more similar than DZ on the "Big 5" personality characteristics of Emotionality, Extraversion, Amiability, Conscientiousness, and Openness (Cohen, 1999; Eaves et al., 1989; Loehlin, 1992). Heritability for attitudes toward traditionalism, sex, and religion are usually about 0.50 and about 0.15-0.30 for taxes, the military, and political interest (Eaves, et al, 1999). While religiosity shows substantial heritability, belonging to a religion has a larger contribution from environment (Eaves et al., 1990).

Personal Family Histories and Repetition of Traits

"I crave eggs when I'm depressed. I just learned that my 40-year-old sister also craves them when depressed and so does my mother."

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This kind of observation is difficult: formal studies allow estimates of heritability for a group of similar individuals on a particular trait in particular conditions.(4) Studies usually do not tell us about traits that sometimes run in families but not always, are probably inherited, but may not ever be seen again. Emergenesis refers to such traits that might result from chance combinations of genes. Exceptional talent draws forth this explanation, we usually miss the trivial examples. (5)
Weiner, however, tells of a young man who returned from France to his ancestral home in Africa where his grandfather was village chief. The old man and the younger one were so alike that the younger was appointed to be the next chief.(6)

Small things assemble into larger things, whether stores in mall or the bricks of our character. Nearly all of us have our own version of these two stories...

Linda

" A 40-year-old woman reared by her mother and a stepfather was battling breast cancer. Linda required a thorough medical history, which meant seeking out her biological father whom she had never known...

"There were the expected physical resemblances; her son was the spitting image of her father. There were also surprising psychological resemblances, some evident in his characteristic behaviors and talents; like Linda, he, too, was an artist. Some resemblances were evident in her father's environment, in little things like the precise arrangement and selection of his books or hearthstone utensils. And something more intriguing: Both Linda and her father had a pet named Winston, clearly not a common name. And, both loved to eat Snickers bars, which is rather more common, but also both couldn't stand peanut butter or chocolate, which is rather unusual. It was, she said, like finding herself in him and his world.

"Linda's biological father shared many of her attitudes, sentiments, interests, sense of humor, and energetic way of doing things. Both were on the intellectual side, conservative in their politics, but liberal in their religious philosophy. Linda and her biological father showed the same characteristic energy, curiosity, enthusiasm for details, and perfectionism on projects. On trips, the both checked out every trail, museum, and ruin.

"Linda and her biological father loved sports, freely venting their emotions in the heat of the moment...After one particular play (football), they both jumped up, waved their arms, and yelled in the same gleeful way. It was as if they had been choreographed. Linda's stepfather watched sports in a reserved, undemonstrative manner, while her mother showed little interest. Linda and her biological father both painted landscapes, she in watercolors, he in oils. Neither her mother nor her stepfather showed more than mild interest in her talent.

"Linda observed that while in physical appearance she favored her mother, psychologically she favored her father. 'I find it especially intriguing that on my wedding day, my mother commented to me, 'Harry would be proud of you; you are so very much like him.' That comment explained away years of frustration and confusion, living in a household which always seemed to be at odds with my psyche."

Edna St. Vincent Millay

Edna and her two sisters, Norma and Kathleen, shared a divorced mother and a nonsupporting, absent father. (In winter, the girls skated in their kitchen on the frozen overflows from the river.) Edna at 12 mothered her sisters while Cora took nurses' aide assignments and wove hair pieces for sale. Cora wasn't home much but she cared for her daughters far longer than another mother would have.

Despite red fingers and nearly freezing, Edna, from age 13-18 years, won prizes for her poetry. She started her first major poem, and perhaps her best, Renasance while still in high school. She won national praise and an invitation to Vassar with full scholarship. Edna thrived in NY culture during a year of remedial work at Barnard. She displayed her red hair, green eyes, and slim figure draped in full length gowns. She thrived on parties, affairs, and smoking. She also gave Vassar faculty a dilemma: she did brilliant work, studied never, and broke most of their social rules. In return, they gave her a diploma but banned her from graduation because of a penultimate infraction. This pattern, having stellar talent but finishing just short of the final prize, occurred many times in her loves and her artistic ambitions.

She roamed between Manhattan, Paris, and the Berkshires for most of her life, recording her rapture in sonnets for every new love. Most of her loves, however, recapitulated her experiences in high school and in poetry contests: she should have been first but often came in with less than the whole prize. Ambivalence? Probably not from fear but from wanting more than one lover, marriage, or focus in her career.

Edna played a mosaic of her mother (who, like her own mother, divorced after an intense flirtation) and father (alcoholic, spendthrift, and dreamer). Despite early, severe deprivation, her talent generated fame and eventually some cash. She cared for her sisters Norma and Kathleen, sending them cash in the style of her mother, as an advance on her royalties. She also managed cash and alcohol in her father's style: she spent and she drank and she had affairs. Edna was joined by her husband in all these activities. Taking pain killers and alcohol and, with her husband's (Eugen) assistance, she spent his resources as well as her own. She eventually fell down the stairs and broke her neck: Eugen was already dead for a year and the wolf once again at her door.(7) She left no children and, in some views, missed first prize one more time.(8)

Such tales, despite their rarity in print and obvious appeal to popular audiences, permeate many of our private conversations and they are easy to elicit when interviewing parents of a distressed child or sparring marriage combatants.

Peter Frost and Hiram Caton put it well on a list serve 4 years ago:
"... People in traditional societies literally believe that they live on in their children and grandchildren. They are not being metaphorical or poetic when they talk this way about their families. In Western societies, we believe that life begins at birth and ends at death. From time to time we still experience feelings that tell us this is not true, but these feelings receive no support from the ambient ideological and cultural environment. If anything we disparage them as relics of a bygone age." Peter Frost, 1/21/98.

"OK, except that the traditional belief is alive and well among many grandparents in modern societies." Hiram Caton, 1/21/98.

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Notes and References

1) I have no doubt that imprinting can help with some of the explanations. Recent news item: French investigators gave anise oil to pregnant women whose babies later did not avoid the flavor. Most children shirk away from it.
2) Plomin, R., DeFries J, McClearn G, and McGuffin, P. (2000) Behavioral Genetics (4th ed.) NY: Worth. Plomin et al. comment there are hundreds of studies and many books on heritability and personality. Depression, criminality, and neuroticism most often draw money for behavior genetics research.
3) Sources in this paragraph were all cited in Plomin, R. (1994) Genetics and Experience: The Interplay between Nature and Nurture. Thousand Oaks, CA: Sage.
4) Plomin, R. (1994) Genetics and Experience: The Interplay between Nature and Nurture. Thousand Oaks, CA: Sage. Plomin, R., DeFries J, McClearn G, and McGuffin, P. (2000) Behavioral Genetics (4th ed.) NY: Worth. Sober, E. (2001) Separating nature and nurture. In D. Wasserman and R. Wachbroit (Eds.), Genetics and Criminal Behavior. NY: Cambridge. pp. 47-78. All provide a balanced explanation of interpreting genetic studies: Sober is perhaps the best as well as the shortest although I remember the rest of that book as disappointing.
5) Lykken DT (1982) Research with twins: the Concept of emergenesis. Psychophysiology, 19(4), 361-373. Lykken, D. (1998) The genetics of genius. In A. Steptoe (Ed.) Genius and the Mind: Studies of Creativity and Temperament. NY: Oxford, pp. 15-38. Lykken, DT, McGue, M, Tellegen, A, and Bouchard, TJ (1992) Emergenesis: Genetic traits that may not run in families. American Psychologist, 47(12) 1565-1577.
6) Weiner, J. (1999) Time, Love, Memory: A Great Biologist and His Quest for the Origins of Behavior. NY: Knopf.
7) Suicide? Or indifference? Preliminary evolutionary research is consistent with the idea of suicide as a response to having no resources, depending on relatives for support, and having no prospects for mates. Buss, D. (1999) Evolutionary Psychology: The New Science of the Mind. NY: Doubleday.
8) Two biographies: Milford, N. (2001) Savage Beauty: The Life of Edna St. Vincent Millay. NY: Random House, and Epstein, D. (2001) What Lips My Lips Have Kissed. NY: Holt. If you have to make a choice or can only stand so much of Edna, Milford's is the better investment.
Brody, J. (1998) Healing the Moral Animal: Lessons from Evolution. 19th Cape Cod Institute, July 20-24, 1998. Taught with Robert Wright, Frank Sulloway, John Fentress, John Pearce, Robin Walker, & Dylan Evans.
Eaves, L., Martin, N, and Heath. (1990) Religious affiliation in twins and their parents: Testing a model of cultural inheritance. Behavior Genetics, 20, 1-22.

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Copyright, 2002, James Brody, all rights reserved.

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