Personality correlates of susceptibility to peer influence in adolescence

Adolescents show a heightened susceptibility to peer influence compared to adults. Individual differences in this susceptibility exist, yet there has been little effort to link these with broader personality processes. Reward sensitivity and impulsive behaviour are also heightened in adolescence and could affect the tendency to be influenced by peers. This study examined associations between self-reported resistance to peer influence, facets of reward sensitivity and impulsivity, and subjective social status in a sample of 269 British sixth form students (mean age 16.79). Multiple regression analyses showed that negative and positive urgency were significantly negatively associated with resistance to peer influence. The relationship between negative urgency and resistance was moderated by subjective social status, such that individuals reporting low status showed a stronger negative relationship. Results suggest that a susceptibility to peer influence is linked with a tendency to act impulsively when in heightened emotional states. Adolescents high in negative urgency who feel lower in their social hierarchy may be particularly vulnerable

Does self-control modify the impact of interventions to change alcohol, tobacco, and food consumption? A systematic review.

Low self-control is associated with increased consumption of alcohol, tobacco, and unhealthy food. This systematic review aimed to assess whether individual differences in self-control modify the effectiveness of interventions to reduce consumption of these products, and hence their potential to reduce consumption amongst those whose consumption is generally greater. Searches of six databases were supplemented with snowball searches and forward citation tracking. Narrative synthesis summarised findings by: consumption behaviour (alcohol, tobacco, food); psychological processes targeted by the intervention (reflective, non-reflective, or both); and study design (experiment, cohort, or cross-sectional). Of 54 eligible studies, 22 reported no evidence of modification, 18 reported interventions to be less effective in those with low self-control, and 14 reported interventions to be more effective in those with low self-control. This pattern did not differ from chance. Whilst self-control often influenced intervention outcomes, there was no consistent pattern of effects, even when stratifying studies by consumption behaviour, intervention type, or study design. There was a notable absence of evidence regarding interventions that restructure physical or economic environments. In summary, a heterogeneous, low-quality evidence base suggests an inconsistent moderating effect of low self-control on the effectiveness of interventions to change consumption behaviours

Impulsivity related personality traits and cigarette smoking in adults: A meta-analysis using the UPPS-P model of impulsivity and reward sensitivity

Background Although there is considerable evidence of an association between impulsivity and cigarette smoking, the magnitude of this association varies across studies. Impulsivity comprises several discrete traits that may influence cigarette use in different ways. The present meta-analysis aims to examine the direction and magnitude of relationships between specific impulsivity-related traits, namely lack of premeditation, lack of perseverance, sensation seeking, negative urgency, positive urgency and reward sensitivity and both smoking status and severity of nicotine dependence in adults across studies and to delineate differences in effects across these relationships. Methods Ninety-seven studies were meta-analysed using random-effects models to examine the relationship between impulsivity-related traits and smoking status and severity of nicotine dependence. A number of demographic and methodological variables were also assessed as potential moderators. Results Smoking status and severity of nicotine dependence were significantly associated with all impulsivity-related traits except reward sensitivity. Lack of premeditation and positive urgency showed the largest associations with smoking status (r = 0.20, r = 0.24 respectively), while positive urgency showed the largest association with severity of nicotine dependence (r = 0.23). Study design moderated associations between lack of premeditation and lack of perseverance and smoking status, with larger effects found in cross-sectional compared to prospective studies. Conclusions Finding suggest that impulsivity is associated with an increased likelihood of being a smoker and greater nicotine dependence. Specific impulsivity-related traits differentially relate to smoking status and severity of nicotine dependence. Understanding the complexity of impulsivity-related traits in relation to smoking can help to identify potential smokers and could inform cessation treatment

Combining trait models of impulsivity to improve explanation of substance use behaviour

The UPPS-P model of impulsivity is gaining popularity among personality and substance use researchers, but questions remain as to whether its five facets have incremental validity in explaining substance use over a more parsimonious model specifying only two facets: reward drive and rash impulsiveness. In three cross-sectional studies (total N = 486), we investigated whether the novel components of the UPPS-P model (negative Urgency, Premeditation, Perseverance, Sensation seeking, Positive urgency) predicted typical and problematic alcohol and cannabis use after accounting for reward drive, rash impulsiveness and trait neuroticism (assessed with the Eysenck Personality Questionnaire). Reward drive and rash impulsiveness scores were calculated using principal components analysis of multiple scales, including UPPS-P premeditation and sensation seeking. Results showed that rash impulsiveness was a robust predictor of typical and problematic substance use. The novel facets of the UPPS-P did not improve prediction of typical substance use. The urgency scales inconsistently predicted problematic use. Specifically, negative urgency predicted one of three measures of negative consequences from alcohol use, and positive urgency only predicted negative consequences from cannabis use. Results suggest that the three novel facets of the UPPS-P model add little over a two component model in explaining substance use, although may provide preliminary evidence for the utility of a revised global urgency construct in explaining problematic substance use

原著

For the purpose of investigating into the influence which is to be exercised by anaerobic bacteria lodged in the intestines of animals on their hosts, experiments were performed on the influence of Cl. welchii in germ-free chicks. Chicks of white leghorn were hatched in a germ-free environment, in chambers made germ-free by sterilization with steam under normal and high pressures. Germless chicks thus obtained were fed on an autoclaved diet, water and vitamins ; since the fifteenth day after being hatched, certain amount of the organisms of Cl. welchii mixed with autoclaved diet had been given to earth germless chicks. During this period, studies were made on the growth, increase in weight and germicidal power of the sera obtained from them. The results are summarized as follows : (1) An environment better suited for breeding germless chicks was provided by a tank designed to be made germ-free by sterilization with steam under high pressure than by one using normal pressure, with the result that the growth of chicks in the former was better than in the latter. (2) Oral administration of Cl. welchii to germless chicks caused diarrhea to take place and also an increase in weight to stop or a decrease in weight to occur. They, however, began to put on weight again in 5 or 7 days. But examinations carried out after a certain period showed that the increase of their weight was lower by about 50 per cent than the increase of weight of the chicks to which Cl. welchii had not been given (controls). (3) Germicidal power of the sera obtained from germless chicks was very low, while that of the sera obtained from the chicks to which Cl. welchii had been given was markedly high. (4) The results of the present experiments indicate that Cl. welchii, when given orally to germless chicks, may exert harmful influence on the growth of their hosts.The fact, however, that the germicidal power of chicks to which Cl. welchii had been given was higher than that of germless chicks suggests that the presence of this kind of bacteria in the intestines of animals may make the hosts more resistant to infection with other pathogenic organisms than otherwise

Impulsivity, Peer Influence, and Adolescent Substance Use

Individuals in Western societies commonly begin to experiment with alcohol and/or cannabis during their adolescent years. Many experience negative consequences from the use of these substances and a minority develop pathological problems such as abuse and dependence. Previous research has identified myriad individual and environmental variables that precede and predict problematic substance use. Two such risk factors are the personality trait impulsivity and the influence of substance-using peers. This thesis aimed to study possible interactive effects of these factors on adolescent alcohol and cannabis use. A systematic review of the literature identified that a trait termed urgency, reflecting emotion-based impulsivity, showed larger associations than other impulsivity-related traits with problematic alcohol use. A study of 270 adolescent students found urgency to be significantly related to problematic alcohol and cannabis use. This study also identified a moderating effect of urgency on the relationship between perceived peer alcohol use and own problematic use. These findings were replicated in a late adolescent undergraduate sample. A three month follow-up of these participants found that urgency also predicted later problematic alcohol use. Next, an experimental study sought to identify social and emotional conditions in which impulsivity-related traits might influence alcohol use more strongly. This study found that an approach-motivated positive mood state and the presence of a friend did not influence trait effects on alcohol consumption in a beer taste test, although a main effect of sensation seeking was identified. The final study of the thesis considered how affective associative thoughts might explain links between urgency, peers, and substance use, particularly amongst adolescents. These findings help to further understanding of the role of impulsivity in adolescent substance use, and contribute to theoretical models of risk for substance use disorders

Impulsivity-related personality traits and adolescent alcohol use: A meta-analytic review

Heightened impulsivity has been identified as a risk marker for excessive and problematic alcohol use, particularly during adolescence when impulsive behaviour is elevated and alcohol use is often initiated. Recent advances in personality theory indicate that impulsivity comprises several discrete traits which may influence alcohol use through different pathways. This review used meta-analysis to assess the degree to which the impulsivity-related traits of lack of premeditation, lack of perseverance, sensation seeking, negative urgency, positive urgency, and reward sensitivity are associated with alcohol consumption and problematic alcohol use in adolescent samples. All traits were positively associated with both alcohol outcomes. Sensation seeking and positive urgency showed the largest associations with alcohol consumption. Positive and negative urgency showed the largest associations with problematic alcohol use, although this was limited to older adolescent samples. A number of demographic and methodological variables were assessed as potential moderators of these associations. Results indicate that excessive alcohol consumption during adolescence may be driven in part by the desire to seek novel and exciting experiences. Problematic use, specifically amongst older adolescents, may be a consequence of a tendency to act rashly when in a heightened positive or negative mood

Trait urgency and substance use decision making in adolescents and young adults: The role of socio-affective factors

The personality trait of urgency has been linked to substance use outcomes. This study examined possible mechanisms underlying this relationship. A total of 187 participants divided into two age groups (adolescents aged 15–17 and young adults aged 18–21) completed measures of urgency and affective associations about substance use. They were then asked to read a hypothetical situation in which a protagonist considers using a ‘legal high’, and to report their perceived peer approval and perceived positive and negative consequences of such substance use, as well as the likelihood that they would personally use the substance. Multiple-group path analysis was employed to test a model by which urgency influenced the substance use decision via affective associations and perceived peer approval. In adolescents, urgency was significantly related to positive affective associations, and a significant indirect path from urgency to decision via affective associations was found. In young adults, there was a significant path from urgency to decision via peer approval. Results indicate that high urgency individuals may rely on socio-affective information when considering whether to engage in substance use

Urgency Traits and Problematic Substance Use in Adolescence: Direct Effects and Moderation of Perceived Peer Use

Negative and positive urgency are facets of trait impulsivity that have been identified as possible risk factors for problematic substance use. Relationships between these traits and substance use measures have not yet been widely investigated in adolescents. In the current study, a sample of 270 adolescent students completed self-report measures of impulsivity-related traits, their alcohol and cannabis use, problematic use, and perceived peer use. Zero-inflated negative binomial regression models indicated that both urgency traits accounted for significant variance in problematic alcohol and cannabis use scores, even after accounting for nonurgency impulsivity traits and typical substance consumption. Furthermore, both urgency traits moderated the positive association between perceived peer alcohol use and individual problematic use. Results indicate that the urgency traits show a direct association with problematic substance use in adolescence, and that high urgency adolescents who believe their peers drink high levels of alcohol may be at increased risk of problematic alcohol use