Temperament, physical activity and sedentary time in preschoolers – the DAGIS study

Background Identifying individual characteristics linked with physical activity (PA) and sedentary time (SED) can assist in designing health-enhancing interventions for children. We examined cross-sectional associations of temperament characteristics with 1) PA and SED and 2) meeting the PA recommendation in Finnish children. Methods Altogether, 697 children (age: 4.7 ± 0.9 years, 51.6% boys) within the Increased Health and Wellbeing in Preschools (DAGIS) study were included. Parents responded to the Very Short Form of the Children’s Behavior Questionnaire consisting of three temperament dimensions: surgency, negative affectivity, and effortful control. PA and SED were assessed for 7 days (24 h per day) using a hip-worn ActiGraph accelerometer, and the daily minutes spent in light PA (LPA), moderate PA (MPA), vigorous PA (VPA), and SED were calculated. The PA recommendation was defined as having PA at least 180 min/day, of which at least 60 min/day was in moderate-to-vigorous PA. Adjusted linear and logistic regression analyses were applied. Results Surgency was associated with LPA (B = 3.80, p = 0.004), MPA (B = 4.87, p < 0.001), VPA (B = 2.91, p < 0.001), SED (B = − 11.45, p < 0.001), and higher odds of meeting the PA recommendation (OR = 1.56, p < 0.001). Effortful control was associated with MPA (B = − 3.63, p < 0.001), VPA (B = − 2.50, p < 0.001), SED (B = 8.66, p < 0.001), and lower odds of meeting the PA recommendation (OR = 0.61, p = 0.004). Negative affectivity was not associated with PA, SED, or meeting the PA recommendation. Conclusion Children’s temperament should be considered when promoting PA in preschoolers. Special attention should be paid to children scoring high in the temperament dimension effortful control.

Temperament, Plasticity, and Emotions in Defensive Behaviour of Paca (Mammalia, Hystricognatha)

Within a species, some individuals are better able to cope with threatening environments than others. Paca (Cuniculus paca) appear resilient to over-hunting by humans, which may be related to the behavioural plasticity shown by this species. To investigate this, we submitted captive pacas to temperament tests designed to assess individual responses to short challenges and judgement bias tests (JBT) to evaluate individuals’ affective states. Results indicated across-time and context stability in closely correlated “agitated”, “fearful” and “tense” responses; this temperament dimension was labelled “restless”. Individual “restless” scores predicted responses to novelty, although not to simulated chasing and capture by humans in a separate modified defence test battery (MDTB). Restless animals were more likely to show a greater proportion of positive responses to an ambiguous cue during JBT after the MDTB. Plasticity in defensive behaviour was inferred from changes in behavioural responses and apparently rapid adaptation to challenge in the different phases of the MDTB. The results indicate that both temperament and behavioural plasticity may play a role in influencing paca responses to risky situations. Therefore, our study highlights the importance of understanding the role of individual temperament traits and behavioural plasticity in order to better interpret the animals’ conservation status and vulnerabilities.

Infant Pain Regulation as an Early Indicator of Childhood Temperament

BACKGROUND: There is considerable variability in infants’ responses to painful stimuli, including facial and vocal expressions. This variability in pain-related distress response may be an indicator of temperament styles in childhood.OBJECTIVE: To examine the relationships among immunization pain outcomes (pain reactivity, pain regulation and parent ratings of infant pain) over the first year of life and parent report of early temperament.METHODS: A subset of parent-infant dyads in an ongoing Canadian longitudinal cohort was studied. Infant pain behaviours were coded using the Modified Behavior Pain Scale. Parental judgments of infant pain were recorded using the Numeric Rating Scale. Infant temperament was measured using the Infant Behaviour Questionnaire-Revised. Correlational analyses and multiple regressions were conducted.RESULTS: Multiple regressions revealed that the 12-month regulatory pain scores predicted parent ratings of the Negative Affectivity temperament dimension at 14 months of age. Parent ratings of infant pain at 12 months of age predicted parent ratings of the Orienting/Affiliation temperament dimension, with sex differences observed in this substrate.CONCLUSION: Pain-related distress regulation at one year of age appears to be a novel indicator of parent report of temperament ratings. Pain outcomes in the first six months of life were not related to parent temperament ratings.

Temperament, character and serotonin activity in the human brain: a positron emission tomography study based on a general population cohort

BackgroundThe psychobiological model of personality by Cloninger and colleagues originally hypothesized that interindividual variability in the temperament dimension ‘harm avoidance’ (HA) is explained by differences in the activity of the brain serotonin system. We assessed brain serotonin transporter (5-HTT) density in vivo with positron emission tomography (PET) in healthy individuals with high or low HA scores using an ‘oversampling’ study design.MethodSubjects consistently in either upper or lower quartiles for the HA trait were selected from a population-based cohort in Finland (n = 2075) with pre-existing Temperament and Character Inventory (TCI) scores. A total of 22 subjects free of psychiatric and somatic disorders were included in the matched high- and low-HA groups. The main outcome measure was regional 5-HTT binding potential (BPND) in high- and low-HA groups estimated with PET and [11C]N,N-dimethyl-2-(2-amino-4-methylphenylthio)benzylamine ([11C]MADAM). In secondary analyses, 5-HTT BPND was correlated with other TCI dimensions.Results5-HTT BPND did not differ between high- and low-HA groups in the midbrain or any other brain region. This result remained the same even after adjusting for other relevant TCI dimensions. Higher 5-HTT BPND in the raphe nucleus predicted higher scores in ‘self-directedness’.ConclusionsThis study does not support an association between the temperament dimension HA and serotonin transporter density in healthy subjects. However, we found a link between high serotonin transporter density and high ‘self-directedness’ (ability to adapt and control one's behaviour to fit situations in accord with chosen goals and values). We suggest that biological factors are more important in explaining variability in character than previously thought.

Personality and Fatigue in Medical Students

Among medical students, fatigue is a common complaint and is related to poor academic outcomes. Associations of scores on personality traits and fatigue in medical students were examined. A group of 125 healthy second-year medical students completed a questionnaire about fatigue, the Japanese version of the Chalder Fatigue Scale, and the Temperament and Character Inventory. On simple regression analyses, the Temperament and Character Inventory dimension of Harm Avoidance was positively associated with Fatigue scores and those on Self-directedness were negatively associated. Similarly, on multiple regression analyses adjusted for age and sex, scores on the Temperament and Character Inventory dimension of Harm Avoidance were positively associated with Fatigue scores, and those for Self-directedness were negatively associated. These correlations were evident even after adjustment for other Temperament and Character Inventory dimensions. The temperament dimension of Harm Avoidance and the character dimension of Self-directedness were both associated with Fatigue in medical students.