Biomedical subjects

Frank Vitaro

Publications and source records attributed to Frank Vitaro.

41 records · Page 3Linked to original sources

PubMed2002

Reactively and proactively aggressive children: antecedent and subsequent characteristics.

BACKGROUND: Reactive and proactive subtypes of aggressive 10-11-12-year-old children were compared with non-aggressive children to examine whether the two forms of aggression were differentially related to antecedent and subsequent measures. METHOD: A large community sample of boys and girls was used. Reactive and proactive aggression was measured through teacher ratings when the children were 10, 11 and 12 years old. Antecedent measures were age 6 temperament and behavioral dispositions; subsequent measures were age 13 delinquency and depressive symptoms. RESULTS: Results indicated that reactive and proactive children had distinctive profiles on antecedent and subsequent measures. CONCLUSIONS: We conclude that children characterized by reactive or proactive aggression differ on several dimensions of personal functioning, and that reactive and proactive aggression are distinct forms of aggression, although both co-occur in a large proportion of aggressive children.

Adolescent↗

PubMed2002

The development of impulsivity, fearfulness, and helpfulness during childhood: patterns of consistency and change in the trajectories of boys and girls.

BACKGROUND: The objective of the present study was to describe the development of boys and girls during the elementary-school years on three dimensions that conceptually and empirically represent risk for maladjustment. METHOD: Every year between kindergarten and grade six, teachers rated the impulsivity, fearfulness, and helpfulness dimensions among a sample of 1,865 children representative of kindergarten boys and girls in the province of Quebec (Canada) in 1986-87. A group-based trajectory method was used to 1) identify groups of boys and girls following distinct-level trajectories of behaviours (on each dimension) during the elementary-school years; 2) estimate the proportion of children in each of the identified trajectory groups; and 3) estimate the patterns of consistency and variations in trajectories. RESULTS: The results indicated that the best models comprised three distinct-level trajectory groups on fearfulness and helpfulness (a low, moderate, and high group) and four distinct-level trajectory groups on impulsivity. The helpfulness and fearfulness trajectory groups were generally more stable than the impulsivity groups. The broad patterns of development were similar across sexes. However, there were more boys on the higher impulsivity trajectories and low helpfulness trajectory, while there were more girls on the high fearfulness trajectory. CONCLUSION: We found that behavioural consistency over middle childhood varied across trajectory groups and across dimensions, and we identified sex differences in the distribution of children in the different trajectory groups that may reflect gender-specific risks for psychopathology.

Child↗

PubMedDate not supplied

Gender differences in developmental links among antisocial behavior, friends' antisocial behavior, and peer rejection in childhood: results from two cultures.

This study addressed gender differences in the developmental links among antisocial behavior, friends' antisocial behavior, and peer rejection. High and increasing, moderate, and low antisocial developmental trajectories were identified among 289 Dutch children, ages 7 to 10, and 445 French-Canadian children, ages 9 to 12. Only boys followed the high trajectory. These boys had more deviant friends and were more often rejected than other children. A minority of girls followed the moderate antisocial behavior trajectory. These girls had fewer deviant friends than moderate antisocial boys, but moderate antisocial boys and girls were equally likely to be rejected. The influence of friends and poor peer relations plays a crucial but different role in the development of antisocial behavior among boys and girls.

Antisocial Personality Disorder↗

PubMedDate not supplied

Examining genetic and environmental effects on social aggression: a study of 6-year-old twins.

Using a genetic design of 234 six-year-old twins, this study examined (a) the contribution of genes and environment to social versus physical aggression, and (b) whether the correlation between social and physical aggression can be explained by similar genetic or environmental factors or by a directional link between the phenotypes. For social aggression, substantial (shared and unique) environmental effects but only weak genetic effects were found. For physical aggression, significant effects of genes and unique environment were found. Bivariate modeling suggests that social and physical aggression share most of their underlying genes but only very few overlapping environmental factors. The correlation between the two phenotypes can also be explained by a directional effect from physical to social aggression.

Aggression↗

PubMedDate not supplied

The unbearable lightness of "light" cigarettes: a comparison of smoke yields in six varieties of Canadian "light" cigarettes.

BACKGROUND: Labelling cigarettes as "light" or "mild" is claimed to be one of the biggest marketing scams in Canadian history. Arguably, such labelling implies that these varieties of cigarettes are less harmful than "regular" cigarettes. In Canada, a food product can be labelled "light" if there is a 25% reduction from the "reference food" and if the constituent being reduced is clearly identified (e.g., light in fat). Cigarette labelling does not comply with these regulations, however. To examine whether or not some tobacco constituents meet the 25% reduction criterion, we compared yields of 41 toxic and/or carcinogenic smoke constituents in six varieties of "light" cigarettes to the yields of "regular" cigarettes. We selected cigarettes from the two most popular Canadian brands, Du Maurier and Players. METHODS: Using a set of data provided by Imperial Tobacco Canada and made available to the public by the Government of British Columbia, we compared yields measured under a laboratory protocol (modified ISO) that was designed to provide a more rigorous evaluation of the differences between varieties of cigarettes and a more accurate assessment of smokers' potential smoke intake than the traditional protocol (standard ISO). FINDINGS: For all six varieties of "light" cigarettes, the yields of nicotine were higher by an average of 5% (range: 1% to 13%). The 25% reduction criterion was not met for any variety of "light" cigarettes concerning yields of tar. For all cigarettes tested, yields of tar were reduced on average by only 16% (range: 5% to 22%). For carbon monoxide (CO), only Player's Smooth Light had an over 25% reduction (30%) compared with Player's Regular. Conversely, yield of CO was 24% higher for Du Maurier Lights compared with Du Maurier Regular. As for the other smoke constituents, the majority (75%) were not reduced by 25% or more in "light" cigarettes, and a sizeable proportion of yields (e.g., acrylonitrile, benzene, chromium, m+p cresol, mercury, nickel, toluene) were larger in these varieties of cigarettes. Only yields of formaldehyde, crotonaldehyde, 1-aminonaphtalene, and proprionaldehyde were systematically reduced in all varieties of "light" cigarettes. CONCLUSION: The six varieties of "light" cigarettes examined in this study do not differ substantially from "regular" cigarettes in terms of smoke yields. We argue that the modified ISO protocol should be implemented for a more valid comparison of potential smoke yields in all varieties of cigarettes and that labelling based on this protocol should be promoted.

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