Day-to-day body-image states: prospective predictors of intra-individual level and variability

Most body-image research has focused on the trait level of body-image evaluation, often neglecting the momentary fluctuations many people experience in everyday life. The present prospective study investigated whether theory-relevant body-image measures, perfectionistic self-presentation, and eating attitudes would predict average day-to-day body-image levels and their intra-individual variability. A convenience sample consisted of 121 women from two universities. In Phase 1 of the study, participants completed an online battery of selected body-image and personality questionnaires. In Phase 2, participants went online to complete the dependent measure, the Body Image States Scale, once per evening over 10 days. As hypothesized, more favorable body-image state levels were associated with less investment in appearance for self-worth, less body-image disturbance, fewer body-image cognitive distortions, less disturbed eating attitudes, and lower body mass. Moreover, greater day-to-day body-image variability was predicted by greater psychological investment in appearance, more body-image cognitive distortions, and higher perfectionistic self-presentation. Implications and future directions for research are discussed.     

The role of within-category variability in category-based induction: a developmental study

The present studies tested the hypothesis that strong assumptions about within-category homogeneity impede children's recognition of the inductive value of diverse samples of evidence. In Study 1a, children (7-year-olds) and adults were randomly assigned to receive a prime emphasizing within-category variability, a prime emphasizing within-category similarities, or to not receive a prime. Only following the variability prime, children demonstrated a reliable preference for evaluating diverse over nondiverse samples to determine whether there is support for a category-wide generalization. Adults demonstrated a robust preference for diverse samples in all conditions. These effects extended beyond the specific categories included in the prime, as well as to multiple types of test questions. Study 1b demonstrated that priming variability leads children to select diverse samples only when doing so is informative for induction. Implications for conceptual development are discussed.     

Inter-individual differences in intra-individual variability in personality within and across contexts

This study focuses on intra-individual variability in personality at work, and how it relates to job performance. 288 professionals completed contextualised adjective-based personality assessments in work and non-work contexts, and a non-contextualised personality measure. Ratings of their personality were also obtained from colleagues, family members and friends. Supervisors provided performance ratings for 130 participants. Results indicate that personality is context- and source-dependent, and varies systematically within contexts intra-individually regardless of source. Whilst this variability was predictive of some performance criteria when based on other-ratings, overall predictive effects were small in number and size. This study adds to the relatively small body of research on personality variability and performance and contributes to the conceptualisation of personality as a dynamic construct.     

Inter- and intra-individual variability in the kinematics of the back squat

The purpose of this study was to explore the level of inter- and intra-individual variability in the kinematic profiles of the back squat movement among skilled weightlifters. Ten competitive weightlifters volunteered for participation in this study. Barbell velocity (V_Barbell) and angular velocity of the ankle (ω_Ankle), knee (ω_Knee) and hip joint (ω_Hip) were obtained by kinematic recording of six trials at 90% of 1RM in the back squat. Inter-individual variability was assessed by analysing inter-individual differences in the velocity curves through the statistical parametric mapping method. Intra-individual variability was assessed through a correlation analysis between the barbell velocity curves of each trial for each participant. Partial least squares regression analysis, was performed to relate changes in intra-individual variability to movement and anthropometric characteristics. Significant inter- and intra-individual differences were identified in V_Barbell, ω_Ankle, ω_Knee, and ω_Hip (p ≤ 0.05). Having a short trunk and thigh, and a long shin in combination with greater anterior-posterior displacement of the barbell and slower velocities during the acceleration phase increased intra-individual movement consistency over movement variability. The results of the present study clearly demonstrate that skilled weightlifters display both significant inter- and intra-individual variability in the successful execution of the back squat.     

Explaining intra-individual variability in social behavior through idiographic assessment: The case of humor

Much variability in social behavior is intra-individual; people vary their actions strategically across contexts. Yet most personality assessment methods are inter-individual; they chart between-person differences in average behavioral tendencies. The present research advanced novel idiographic assessment methods to predict intra-individual variability in a behavioral domain of long-standing interest to personality psychologists: humor. Individuals participated in three assessment sessions. Personal beliefs about reasons for using humor were assessed either idiographically or with respect to a nomothetic system of humor-related reasons for action. The subjective relevance of nomothetically- and idiographically-identified reasons to everyday social situations was assessed. Subsequently, participants reported their perceived likelihood of using humor in specific social contexts. As predicted, likelihood of humor use varied substantially as a function of the relevance of situations to idiographically-identified reasons, but did not vary as a function of the relevance of situations to reasons identified nomothetically. Implications for personality and assessment are discussed.     

Word-list-learning performance in younger and older adults: intra-individual performance variability and false memory

We investigated the word-list-learning performance of younger and older adults over 4 consecutive days at different times of day to study age-related differences in consistency of performance over time and the influence of circadian variation on performance. Eighteen younger (M age, 23.4 years) and 18 older (M age, 73.3 years) men and women participated. The start time of testing alternated between morning and early evening across the 4 days of testing. On each test day, participants learned a different list of 15 unrelated words over four learning trials. As expected, younger adults performed better than older adults on immediate recall, delayed recall, and recognition. Contrary to our expectations, time of day did not significantly influence recall or recognition performance in either the older or younger adults. Older adults did show a greater incidence of false memory (i.e., previously learned list intrusions in free recall and false alarms in recognition) than younger adults. Older adults also exhibited greater intra-individual performance variability on the measures of false memory across test days. This variability was not related to circadian variation. False memory and variability of performance have both been linked to frontal systems dysfunction. The findings presented here are consistent with the notion that changes in cognition with aging in part reflect age-related decline in frontal lobe function.     

Differential effect of lesion side on intra-individual variability in children with focal lateralized epilepsy

A differential impact of hemispheric side (left vs right) on cognitive measures, specifically Verbal and Performance IQ, has been described previously for both focal onset seizures and lateralized brain lesions. This study revealed a differential effect on intra-individual variability, measured as subtest scaled-score range, on the Dutch WISC-R and WISC-III, in children with epilepsy. The presence of documented brain lesion was associated with elevated variability on the Verbal Scale for the left hemisphere seizure group and with decreased variability on the Verbal and Full Scales for the right hemisphere seizure group.     

Inter-individual and intra-individual variability of the N2 component: On reliability and signal-to-noise ratio

The nogo N2 component, an anterior negative peak supposed to be generated in the anterior cingulate cortex, has been used as an indicator of conflict monitoring and response conflict in basic and clinical research. Here, we investigate the reliability and the signal-to-noise ratio (SNR) of inter-individual differences of the N2 amplitudes as well as of intra-individual standard deviations of N2 amplitudes. Effects of the number of nogo epochs, type of summary measure (peak vs. average amplitude), and filter cut-offs (1–12 Hz vs. 1–30 Hz) are investigated. A sample of N = 32 participants, performed a go/nogo task. Excellent Cronbach’s alpha coefficients (?.90) were obtained for the fronto-central average N2 amplitude at 40 nogo epochs and for the peak N2 amplitude at 60 nogo epochs. The SNR was higher for the average nogo N2 amplitude compared to the peak N2 amplitude. Split-half reliability coefficients of the intra-individual standard deviation of the nogo N2 amplitudes were at least moderate. Based on these results we provide suggestions for a reliable N2 measurement. Moreover, although intra-individual variability has often been conceived as noise the present findings support the idea that intra-individual N2 variability incorporates systematic variance.     

Modeling continuity and discontinuity in utterance length: a quantitative approach to changes, transitions and intra-individual variability in early grammatical development

The confluence of an anomaly such as a growth spurt or a temporary regression on the one hand and a temporary increase in intra-individual variability on the other hand, forms a strong indicator of a major transition in early language development. Data concern one-word (W1), two- and three-word (W2-3), and four-and-more-word (W4+) utterances from two French children during their second and third years. A dynamic growth model was fitted, based on a structure of supportive, conditional and competitive relationships. Using a statistical simulation method, we showed two striking peaks of variability in addition to a temporary regression or rapid growth in the proportions of W1, W2-3 and W4+ utterances. We argue that these phenomena show transitions corresponding to critical points in grammatical development, which could be indicative of the emergence of simple combinatorial and syntactic stages of language successively. Our results emphasize the relevance of time-serial data and of intra-individual variability in the study of developmental transitions in general.     

An investigation of intra-individual variability in children with fetal alcohol spectrum disorder (FASD)

Intra-individual variability (IIV) is defined as systematic within-person variation in performance either across test sessions (e.g., test/retest performance on the same task) or in one session (e.g., variations in performance on multiple trials of a single task). Higher levels of IIV have been noted as a characteristic of neurodevelopmental disorders such as attention deficit/hyperactivity disorder? (ADHD), but IIV is yet to be investigated in fetal alcohol spectrum disorder (FASD). FASD is a term used to describe a range of conditions resulting from prenatal exposure to alcohol. As part of a comprehensive neuropsychological battery, four study groups (1. fetal alcohol syndrome/partial fetal alcohol syndrome; 2. static encephalopathy/alcohol exposed; 3. neurobehavioral disorder/alcohol exposed as diagnosed using the University of Washington FASD 4-Digit Code; 4. typically-developing (TD) age-matched children with no prenatal alcohol exposure) were administered measures of motor response and inhibitory control, attention, and adaptive behavior. The results indicate increased levels of IIV in those with FASD compared to the TD controls. It was found that IIV uniquely contributes to predicting adaptive behavior above and beyond attention, while attention partially mediates the relationship between IIV and adaptive behavior. This is the first study to the authors’ knowledge to show the presence of increased IIV in children with FASD. It additionally provides evidence that IIV measures some inherent variability in performance independent of poor attention in children with FASD.     

A longitudinal study of basal cortisol in infants: Intra-individual variability, circadian rhythm and developmental trends

Mothers with normally developing babies were visited in their homes during 13 consecutive weeks, when the babies were around 5–8 months of age. Basal salival cortisol measures were taken for both the baby and the mother on arrival.The infants’ basal cortisol decreased linearly with age, was negatively related to sleep, and did not show adult-like circadian declines from morning to mid-afternoon. Furthermore, while the infants showed relative stability across individuals, they displayed great intra-individual variability across assessments. Contrarily, the mothers displayed important inter-individual variability, together with a relative stability across assessments. The infants’ important intra-individual variability was not affected by gender, nor time of visit, nor was it related to the mothers’ basal cortisol. Daily measures of basal cortisol taken in a subgroup of infants indicated the day-to-day intra-individual variability to be of the same magnitude as the week-to-week variability.The question of how the intra-individual variability in basal cortisol affects assessments of cortisol in infancy is addressed. The aggregation of data with the goal of increasing the reliability of the assessments is shown to be inadequate for infant basal cortisol.     

Body image ups and downs: prediction of intra-individual level and variability of women's daily body image experiences

This investigation assessed body image states in the context of everyday life among 108 college women. Participants initially completed measures of body image traits and eating attitudes and subsequently called an automated telephonic response system twice daily for 6 days to convey current body image experiences on the Body Image States Scale. The research examined the extent to which selected pretest variables predicted the level and variability of body image states. As hypothesized, less favorable body image state levels were associated with lower trait body image satisfaction, more body image dysphoria, more dysfunctional investment in appearance, more disturbed eating attitudes, and the use of less adaptive and more maladaptive body image coping strategies. Also as expected, body image variability was predicted by psychological investment in one's appearance, disturbed eating attitudes, and appearance-fixing coping strategies. Implications of the results and future research directions are discussed.     

Theory and data on developmental changes in novelty preference

The present study was designed to investigate the predictive value of an informational analysis of vicarious consequences. Two levels of amount of vicarious consequences (complete, partial) were varied with three types of vicarious consequences (reward, punishment, reward-punishment). Each of six groups of preschool age boys and girls observed an adult male model receive one of the combinations of amount and type of vicarious consequences for his choices from a commodity preference series. A seventh group of boys and girls observed the model receive no consequences for his choices. After observing the model, each subject was asked to make his own choices from the commodity preference series and to recall the choices which the model made. In contradiction to the predictions of an informational analysis of vicarious consequences, the amount of vicarious consequences did not differentially affect the recall of modeled behavior while the type of vicarious consequences did have a differential effect.     

Beyond stability: Predicting inter-individual differences in intra-individual change

Demonstration of a high longitudinal stability of inter-individual diferences in behaviour has been one traditional goal of personality psychology. In recent years, impressively high longitudinal correlations have been reported for self-and other-ratings of behaviour in adulthood, indicating a high overall stability of personality differences in that period of development. However, even 5-year correlations around 0.70 do not exclude major deviations of some of the subjects from this overall stability (i.e. differential stability in the sample). Furthermore, the younger a sample is, the lower will be the longitudinal stability observed, and the less suficient is the explanation of inter-individual diferences by static traits. This article goes beyond the notion of stability at the sample level by asking from a developmental perspective (a) whether systematic inter-individual differences in intra-individual change exist, (b) how they can be assessed, and (c) whether these inter-individual differences can be explained by characteristics of the person or of the environment.     

Listening to distraction: a developmental study of selective attention

One hundred eight children 8, 11, and 14 years old selected one auditory message from two (male-female voice cue). Retention of target and distracting words was tested. Fifty-four control Ss heard the target message alone. Contrary to some earlier studies, distraction hindered the target performance of younger children more than older children. In the experimental groups target retention increased linearly with age but distraction retention remained constant. Intrusions from the distracting message during the selection task decreased greatly with increasing age. These and other results were interpreted as showing that the superior selective listening performance of older children is due not to a greater ability to filter out distracting material at an early stage of processing, but in large part to an ability to inhibit intrusions from the distracting material during the selection task.     

Prospective Memory: A New Focus for Research

Prospective memory is required for many aspects of everyday cognition, its breakdown may be as debilitating as impairments in retrospective memory, and yet, the former has received relatively little attention by memory researchers. This article outlines a strategy for changing the fortunes of prospective memory, for guiding new research to shore up the claim that prospective memory is a distinct aspect of cognition, and to obtain evidence for clear performance dissociations between prospective memory and other memory functions. We begin by identifying the unique requirements of prospective memory tasks and by dividing memory's prospective functions into subdomains that are analogous to divisions in retrospective memory (e.g., short- versus long-term memory). We focus on one prospective function, called prospective memory proper; we define this function in the spirit of James (1890) as requiring that we are aware of a plan, of which meanwhile we have not been thinking, with the additional consciousness that we made the plan earlier. We give an operational definition of prospective memory proper and specify how it differs from explicit and implicit retrospective memory and how it might be empirically assessed.     

Olfactory categorization: A developmental study

This study examined the ability of children to classify fruit and flower odors. We asked four groups of children (4-11years of age) and a group of adults to identify, categorize, and evaluate the edibility, liking, and typicality of 12 fruit and flower odors. Results showed an increase in interindividual agreement with age for the taxonomic (fruit/flower) and function-based (edible/nonedible) categories but not for the hedonic component. So, it seems that this hedonic component is not the explicit basis for this increase in interindividual agreement when categorizing an odor as a fruit/flower odor or as being edible or nonedible. An age-related trend was also observed on the typicality scores: The youngest group of children did not show a typicality gradient, but all of the other groups did. Blackcurrant and lemon were rated as the most typical fruit odors, whereas raspberry and peach were rated as the least typical. For flower odorants, results were not as clear, yet it seems that for all groups lavender was considered as quite typical.