Collectively, our results show that three out of the Big Five dimensions of personality (openness to experience, conscientiousness, and extraversion), gender, and GPA have a unique and statistically significant contribution to students’ involvement in undergraduate scientific research activities.
To the best of our knowledge this is the first study to consider the contribution of student’s individual characteristics to engagement in undergraduate scientific research activities. Also, this study takes into consideration a student’s actual research participation behavior, rather than future intentions of participation or positive attitudes towards research and science [12, 13].
Although the associations observed were statistically significant, they were modest, which is not surprising given the complexity of human behavior. That is, other individual and contextual factors might influence student’s engagement (e.g. students’ autonomy levels or availability of role models amongst the faculty). In fact, previous studies determined that personality variables usually account for about 14% of the variance in behavior . Our model, by adding other individual characteristics to personality traits, explained 33% of the variance, thus adding an important dimension to the understanding of complex decision-making behaviors.
Personality predicts behavior to the extent that it can influence the psychological state of an individual and predispose him to action. Considering that “open individuals” are characterized as being intellectually curious, creative, and more adaptable to novel situations, their higher involvement is congruent with the type of work and intellectual curiosity demanded by scientific research. Motivation, persistence, careful planning, and the ability to delay gratification are important traits for this activity and are common to individuals with high conscientiousness scores; thus, it is not surprising that both openness and conscientiousness positively influence students’ participation. In contrast, “extroverted individuals” tend to value more socially stimulating activities and are less likely to concentrate on demanding cognitive tasks, which is likely to explain a smaller involvement of highly extroverted individuals .
Higher GPA was linked to greater engagement in research. One of the reasons underlying this relation might be that students with higher GPAs could be more confident in their ability to use their transferable skills (for example, communication skills and time management) to tackle the demands that come with scientific research participation.
Also, results showed that male students are more likely to be involved in research. Gender imbalances in engagement have been reported  and might be caused by cultural and social factors that keep women from participating (for example, lower levels of autonomy and unavailability of female role models) or by different self-perceptions of competence between males and females. In fact, a study by Burgoyne et al.  demonstrated that male students felt significantly more competent in transferable and research-specific skills and biological statistics. It is also possible that female students are more focused on academic performance and prefer to invest their time and efforts in what they perceive to be more curriculum-related activities. Interestingly, the categorization of two sub-samples according to the type of involvement (elective curricular or extra-curricular), revealed the proportion of women engaged in scientific research in extra-curricular settings was even lower. However, this proportion increased if we only considered the female students with lower “conscientiousness” scores, suggesting that female students might be more focused on curricular performance.
Besides finding the effect of individual characteristics on undergraduate scientific research activities engagement, we found that some of these dimensions (gender, conscientiousness, openness, and GPA) are also related to the type of extra-curricular involvement students choose, which further strengthens our findings. Interestingly, parents’ education was also a factor that influenced student engagement in extra-curricular undergraduate scientific research activities. In fact, for males, being a “first generation student” seems to have an impact on the type of involvement they choose to have. Available data from other studies points in different directions: first generation students were found to have lower educational aspirations and to be less involved in campus activities . However, these studies were not done with medical students and it is quite possible that the very demanding selection process for medical school admission might be selecting first generation students for whom their family’s educational background is not relevant for their educational attainment. Also, changes in the Portuguese educational, social, and economic reality in the past two decades might mean new career opportunities for first generation students, encouraging them, and their families, to invest in different activities that can contribute to their professional success.
If one assumes that student engagement in research is a positive behavior that should be encouraged, taking student characteristics into consideration might result in more targeted efforts of recruitment and hold greater promise in contributing to the sustainability of the physician-scientist career pipeline.
Caution must be used in making generalizations from the study results in light of the following limitations. Although the participants in our study were exposed to similar curricula, faculty, staff, and educational opportunities (all of which can be discarded as confounding factors in the present study), they all originated from one single institution. Even though we considered the number of opportunities the students had to engage in research, the fact that not all of the students were in the same curricular stage is a limitation. Bootstrap analysis supports the validity of our regression model, but further confirmation in prospective studies and with future cohorts of students is needed to further address the issue. Because the number of students engaging in research activities is low, our CRT sample was small. For that reason, no cross-validation method was used and we allowed small minimum numbers of subjects in the child nodes. Further analysis with greater samples is crucial. Future studies that take into account these shortcomings will certainly contribute to a better definition and characterization of the best predictors of engagement in research activities. Our study discards all variables related to institutional context and it also does not explore subsequent behavior of engagement exhibited by the students (e.g. abandoning research after they have engaged versus maintaining the behavior in a consistent manner). Future qualitative research might give an insight on other important variables associated with student’s engagement in scientific research.