Recognition of static and dynamic facial expressions: Influences of sex, type and intensity of emotion

Ecological validity of static and intense facial expressions in emotional recognition has been questioned. Recent studies have recommended the use of facial stimuli more compatible to the natural conditions of social interaction, which involves motion and variations in emotional intensity. In this study, we compared the recognition of static and dynamic facial expressions of happiness, fear, anger and sadness, presented in four emotional intensities (25 %, 50 %, 75 % and 100 %). Twenty volunteers (9 women and 11 men), aged between 19 and 31 years, took part in the study. The experiment consisted of two sessions in which participants had to identify the emotion of static (photographs) and dynamic (videos) displays of facial expressions on the computer screen. The mean accuracy was submitted to an Anova for repeated measures of model: 2 sexes x [2 conditions x 4 expressions x 4 intensities]. We observed an advantage for the recognition of dynamic expressions of happiness and fear compared to the static stimuli (p < .05). Analysis of interactions showed that expressions with intensity of 25 % were better recognized in the dynamic condition (p < .05). The addition of motion contributes to improve recognition especially in male participants (p < .05). We concluded that the effect of the motion varies as a function of the type of emotion, intensity of the expression and sex of the participant. These results support the hypothesis that dynamic stimuli have more ecological validity and are more appropriate to the research with emotions.

The Proliferation of Paramilitary Groups in Southern Mexico: State Strategy or Struggle between Local Political Elites?

This study traces the origins of Mexican paramilitary groups and argues that, contrary to what most of the literature on the subject implies, they do not represent a state strategy to thwart leftist groups seeking social change. Rather, they represent battles between groups of national and local-level elites with different visions of democracy and of what constitutes good governance. The polarization inherent in this type of conflict leads local actors to have to side with one faction of elites or the other. The presence of radical leftist groups in recently colonized indigenous areas with scant state presence gives rise to a process of radicalization among local elites. There are multiple factors that explain the emergence of paramilitary groups. Aside from the post Cold War international context, there were national factors like a shift in its focus away from security matters between 1989 and 1993, and presidential policies between 1968 and 1993, that planted the seeds of leftist radicalism in a context of id modernization