Try out PMC Labs and tell us what you think. Learn More. Five Factor Model FFM personality traits are implicated in long-term health-risk behaviors and outcomes. Less research has addressed how early-life experiences are associated with individual differences in these traits in adulthood. We examine whether having been breastfed is associated with adult personality and well-being in the National Longitudinal Study of Adolescent to Adult Health. At Wave 1, caregivers reported whether the target child had been breastfed. Participants who had been breastfed scored lower in neuroticism, anxiety, and hostility and higher in openness and optimism than those not breastfed.
Breastfeeding was unrelated to conscientiousness or state psychological functioning. This research suggests long-term psychological benefits to breastfeeding and indicates that early life experiences are associated with traits that are consequential for adult health. The personality traits that define the Five-Factor Model FFM of personality — neuroticism, extraversion, openness, agreeableness, and conscientiousness — are routinely implicated in health-risk behaviors and outcomes.
In addition to these two traits, individuals high in antagonism i. These health correlates of personality are well documented; much less is known about the antecedents, particularly early-life antecedents, of these traits.
In contrast to estimates from behavioral genetics, molecular genetics studies have found more modest genetic effects. Other biological factors may play a larger role in the development of the traits than genetics. Early life experiences, either through biology or through experience, may be associated with the development of these traits. Eating is among the first behaviors that newborns engage in following birth, and many positive health-related outcomes have been linked with breastfeeding.
Children who are breastfed, for example, are less likely to become obese, are less prone to infection, and have fewer respiratory problems Ip et al. This protective effect of breastfeeding extends to other domains beyond physical health. Children who are breastfed for longer durations score higher on tests of cognitive functioning in young Julvez et al.
There is also growing evidence that breastfeeding may be related to psychological functioning and adjustment. Similar to the adult and cognitive health benefits of having been man, the protective effect on mental health may continue into adulthood.
And, although less research has addressed whether breastfeeding is associated with adult personality traits, as defined by the FFM, there is evidence that breastfeeding is associated with some FFM-related traits. In a large sample of adults from Finland, for example, those who had been breastfed scored lower in hostility-related traits than those who had been fed with a bottle Merjonen et al. The present study takes an intergenerational life-course perspective to examine whether breastfeeding is associated with trait psychological functioning in adulthood, defined as the characteristic ways of thinking, feeling, and breastfeeding operationalized by the FFM.
In addition, given that there is some evidence that having been breastfed is associated with less psychological distress in adulthood Cable et al. Since breastfeeding tends to be protective against internalizing disorders in childhood Liu et al. Likewise, based on research Merjonen et al.
We construe the effect of breastfeeding on the other traits as exploratory. To examine whether there is a dose-response to breastfeeding or whether a single exposure at birth is sufficient for an association with personality, we test whether the duration of breastfeeding none to more than 24 months is associated with mean levels of the traits. Since some research has indicated that the association between breastfeeding and distress is limited to female offspring Cable et al.
We use a large national sample that has caregiver reports of breastfeeding and self-reported trait and state psychological functioning man young adulthood to test these hypotheses. Participants in Add Health were recruited as a nationally representative sample of adolescents in the United States in grades 7—12 during the — school year. The fourth and most recent wave of data collection occurred in — This wave was the first to include a measure of personality traits described below ; other measures of trait and state psychological functioning were also available from this wave.
Due to missing data on some variables, the analytic sample size ranged from 13, to 13, For adult analyses, the responses were dichotomized as any breastfeeding versus not breastfed. Each domain is measured with four items. Although the reliability tends to be lower than longer personality measures, the mini-IPIP has adequate reliability in young adult populations in general Donnellan et al.
Anxiety and angry hostility were measured breastfeed 4 items each from the anxiety e.
Optimism was measured with 4 items e. All ratings were made on a scale that ranged from 1 strongly agree to 5 strongly disagree and were reverse coded such that higher ratings indicated greater agreement. Items e. A short version of the Center for Epidemiological Studies Depression scale Radloff, was used to assess depressive symptoms and well-being. Participants rated 5 items that captured the frequency of negative affect e.
The items were rated on a 4-point scale from 0 rarely or never to 3 most or all of the time and scored separately as depressive symptoms and well-being. We used analysis of covariance ANCOVA to examine whether there were differences in trait and state psychological functioning between participants who were breastfed regardless of length and those who were not breastfed.
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Pairwise comparisons were used to examine man any mean-level differences by duration were statistically ificant. We first compared whether there were mean-level differences in psychological functioning between participants who had been breastfed regardless of duration versus those who were exclusively bottle-fed Table 1.
The were nearly identical when the early life control variables e. The one exception was that the difference between the two groups on agreeableness was reduced to non-ificance; all other differences breastfeeded ificant. The for personality were also similar when controlling for the other traits, again with the exception of Agreeableness. None of these associations was moderated by sex, which indicated that the association between breastfeeding and differences in psychological functioning in adulthood were similar for men and women.
N s range from 13, to 13, Estimated marginal means standard errors of psychological functioning by feeding type from analysis of covariance. Model 1 controls for participant age, sex, race, and education. We next examined whether there were differences in psychological functioning by the length of breastfeeding Table 2. For neuroticism, there was evidence of a curvilinear association between breastfeeding duration and mean-level of Neuroticism Figure 1a : For each three month increase in the duration of breastfeeding, there were lower scores on Neuroticism until adult 9—12 months when Neuroticism scores increased.
Each duration of breastfeeding was associated with ificantly lower Neuroticism compared to participants who had not been breastfed, with the exception of the longest duration of breastfeeding. Participants who had been breastfed for more than 24 months had similar mean levels of Neuroticism as those who had not been breastfed.
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For Openness, the only ificant difference matched the analysis of none versus any breastfeeding: For each duration of breastfeeding, Openness scores were higher compared to no breastfeeding, with some evidence that an extended period of being breastfed was associated with even higher Openness Figure 1b. The mean differences by duration, however, were not ificant. For anxiety, hostility, and optimism, the only differences to emerge were between not having been breastfed and all other durations of breastfeeding, but not between the breastfeeding durations.
Similar to the dichotomous breastfeeding analysis, there were not ificant differences by length of breastfeeding for perceived stress, depressive symptoms, or well-being. Estimated marginal means standard errors of psychological functioning by feeding duration from analysis of covariance that controls for participant age, sex, race, and education. Rows without subscripts do not have any ificant differences between the means. The present research used a large sample with caregiver reports of breastfeeding and psychological functioning measured in adulthood to identify the long-term psychological correlates of being breastfed.
Participants who had been breastfed in infancy scored lower on traits related to negative emotionality i. These differences persisted even after controlling for socio-demographic factors that may confound the relation. There was no evidence that breastfeeding was associated with state psychological functioning, such as depressive symptoms or well-being. Of note, we found no association between breastfeeding and adult conscientiousness, the most consistent personality predictor of health outcomes.
Conscientiousness tends to be associated with similar health outcomes as breastfeeding: Individuals who are conscientious or breastfed tend to have lower BMI Fergusson et al. Although both conscientiousness and breastfeeding are associated with better physical health, it appears that the relations are through different pathways. That is, Conscientiousness is not the mechanism that le from breastfeeding to better health outcomes, but is rather an independent predictor.
The null relation between breastfeeding and extraversion was likewise surprising and counter to our hypothesis. The protective association of breastfeeding to emotional functioning may be limited to regulation of negative affect i. Extraversion is a heterogeneous trait that encompasses gregariousness, positive emotionality, warmth, activity, and excitement seeking. Yet, the items that measure extraversion on the mini-IPIP solely reflect its gregariousness component. Thus it may be the case that breastfeeding is associated more with the optimistic, positive emotionality aspects of extraversion rather than the sociability component.
There was also no evidence that breastfeeding was associated with state psychological functioning in adulthood. This null finding was somewhat surprising since several studies have shown that breastfeeding is associated with fewer internalizing disorders in childhood Oddy et al. It is possible that better regulation of mood develops throughout childhood and becomes cemented as a trait by early adulthood. In this case, breastfeeding may be associated with stable psychological functioning e.