The experience of the pandemic caused by the Coronavirus and the consequent disease triggered by it (COVID-19) brought to light fragilities that have been long overlooked by the scientific community and by various political and social institutions. The pandemic also brought to the fore certain social practices resulting from individual behaviors, such as wearing a mask and practicing social isolation. It demonstrated the need for social commitment and pro-social behaviors if societies are to respond successfully. The purpose of this article is to evaluate psychological and sociodemographic characteristics associated with compliance or noncompliance of individuals with these practices in two different phases of the pandemic experience in Brazil: in the first month and after three months. Participants for the first phase of the study were recruited through advertisements in the media and social networks. 1,914 individuals aged between 14 and 81 years agreed to participate, 78.2% of these were women, from 25 Federative Units in Brazil. In the second phase, 761 individuals who participated in the first phase, were reassessed. The authors used the following instruments for data collection: a standardized questionnaire collecting information of sociodemographic characteristics and dynamics of social isolation; the Kessler Psychological Distress Scale; the Life Satisfaction Scale; the Positive and Negative Affections Scale; and the Reduced Personality Markers and Stress Mindset Scale. All instruments used presented evidence of validity and adequate reliability indexes. The comparison of categorical exploratory variables with motives for following social isolation protocols was performed using Pearson’s Chi-square, and the comparison of continuous exploratory variables was performed using the Mann-Whitney test. Covariance Analysis was performed using as covariates those that showed significance/effect on isolation in previous analyses. The results showed that respondents practicing social isolation to comply with governmental recommendations had lower scores on the scales of neuroticism and conscientiousness. They reported also less stress, anxiety, and depression, and less general distress. Overall, these respondents also displayed more positive affect, and tended to reframe stress in a more positive way than others. These preliminary results describe the psychological characteristics of individuals and their associations with social behaviors in a period of collective stress and high social risk.