In a new study published last March in the Journal of Child Psychology and Psychiatry, Harvard researchers reveal that even a single incident of malnutrition in early childhood can have a profound effect on an individual’s adult personality. Individuals who had suffered from severe starvation as infants tended to be more neurotic and less adventurous, sociable, curious, and organized as adults.

The study monitored the growth and development of a group of 77 children who had been hospitalized due to malnutrition within the first year of life and a group of 57 healthy controls from the same neighborhoods and socioeconomic backgrounds. When they reached the age of 40, the personalities of the study’s participants were evaluated for five main traits: neuroticism, extroversion, openness, agreeableness, and conscientiousness.

Though the individuals monitored had only suffered from malnutrition for only a short period very early on, the study still found striking differences between the previously malnourished individuals and the control group. The profiles of previously malnourished individuals were five times as likely to indicate neurotic personalities as their healthy counterparts and three times as likely to exhibit low levels of extroversion and conscientiousness. Individuals who hadn’t suffered from malnutrition were five times more likely to have high scores for openness.

According to Janina R. Galler, lead author and psychiatry professor at Harvard Medical School, the results were shocking.

“These personality profiles suggest that these people may have mental health issues at this point in their life,” said Galler.

Though the exact biological connection between childhood malnutrition and adult personality remains a mystery, the research team suspects that childhood malnutrition may limit the production of important proteins and nutrients crucial for the normal development of the brain during early childhood.

Galler said that the effects of childhood malnutrition on personality may extend even to the next generation. In parallel animal studies, the research team found that both animals who had suffered from malnutrition in childhood and their offspring suffered personality impairments. The researchers hope to study the personalities of the children of the original study participants to evaluate if the same trans-generational effect is present in humans.

According to Galler, the study suggests that intervention programs which provide proper nutrition to malnourished children cannout guarantee their future mental health.

“What it means is that there is really no quick fix for early malnutrition,” said Galler, “We really have to think much more broadly in terms of how public health policies dealing with malnutrition should be crafted.”