Malnutrition in the first year life, even when followed by a good diet and restored physical health, predisposes people to a troubled personality at age 40, new research suggests.
The study of 77 formerly malnourished people represents the first evidence linking malnutrition shortly after birth to adult personality traits. The traits in some cases may foretell psychiatric problems, says a team led by psychiatrist Janina Galler of Harvard Medical School in Boston and psychologist Paul Costa of Duke University Medical Center in Durham.
Compared with peers who were well-fed throughout their lives, formerly malnourished men and women reported markedly more anxiety, vulnerability to stress, hostility, mistrust of others, anger and depression, Galler’s team reports March 12 in the Journal of Child Psychology and Psychiatry. Survivors of early malnutrition also cited relatively little intellectual curiosity, social warmth, cooperativeness and willingness to try new experiences and to work hard at achieving goals.
Previous studies of people exposed prenatally to famine have reported increased rates of certain personality disorders and schizophrenia. Another investigation found that malnutrition at age 3 predisposed youngsters on the Indian Ocean island of Mauritius to delinquent and aggressive behavior at ages 8, 11 and 17.
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As is true in the new study, distrust of others, anxiety and depression often accompany high levels of anger, says psychologist Adrian Raine of the University of Pennsylvania in Philadelphia, who directed the Mauritius research. “Poor nutrition early in life seems to predispose individuals to a suspicious personality, which may then fuel a hostile attitude toward others,” Raine proposes.
Galler cautions that her study examined general personality traits in adulthood, not personality disorders as diagnosed by psychiatrists.
The new investigation was part of a long-term health project conducted on Barbados, an English-speaking Caribbean country. Participants included 77 adults who had been admitted to a hospital for malnutrition at about age 7 months. After admission and up to age 12, the kids and their families participated in a government program that provided health monitoring, home visits, nutrition education and food assistance.
Another 57 Barbados adults examined by the researchers were the same age as the formerly malnourished volunteers but had always had enough to eat.
All participants had normal birth weights, suggesting that none endured malnutrition in the womb.
In responses to a questionnaire, about one-third of formerly malnourished adults scored high on a personality measure that taps into anxiety and other elements of emotional distress, versus 7 percent of the comparison group. Similar disparities in favor of the comparison group characterized three other broad personality traits — extraversion, openness to experience and conscientiousness.
This skew toward negative personality characteristics remained after the researchers excluded individuals with low IQs from the malnourished group, indicating that severe intellectual difficulties prompted by early food deprivation did not lie at the root of emotional distress and other personality problems.
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“We were most surprised by the relative pervasiveness of the malnutrition effects” on personality traits, Galler says.
Malnutrition shortly after birth could alter brain growth or activity in ways that shape personality traits later in life, Galler speculates. Or early food deprivation may indirectly influence adult personality by increasing children’s general distress and wariness, boosting vulnerability to poor parenting. While participating in the government intervention, many mothers of formerly malnourished Barbados youngsters reported symptoms of depression, which can undermine child-raising skills.