Every day, people encounter temptations that they need to overcome in order to obtain desirable future outcomes. School children face them when they decide to do their homework instead of watching TV, and adults face them when they decide to save for their retirement rather than enjoy an extensive vacation. What makes it possible to resist temptation some times, but not others? Is it basic brain function and anatomy, some of which may be based on genetic variations? The goal of this research is to understand the cognitive and neural bases of self-control, in particular the ability to override impulsive responding and to delay immediate gratification in the service a delayed, but more desirable, future consequence. The investigators will examine this process in detail at three levels. First, at the level of mental processes, the researchers will examine the extent to which self-control has to do with people's ability (1) to block the entry of unwanted information (e.g., by paying attention to something else), or (2) to suppress unwanted thoughts (e.g., by thinking about something else), or (3) to stop themselves from acting (e.g., by keeping one's hand from moving). Second, self-control processes will be analyzed at the level of brain functioning and anatomy. Past research has identified areas of the brain that become particularly activated when people engage in these processes, as well as connections between areas of the brain that seem to play a key role. These functional and anatomical features will be related to effective self-control strategies, such as shutting out information, suppressing thoughts, and inhibiting behavior. Finally, self-control processes will be examined at the level of genetics. Recent research has found that variations in some genes may be related to people's ability to self-control. Modern technology has made it possible to examine which variation of these genes people have using a simple, non-invasive and cost-effective method, when the target DNA sequences are known. Using such methods, the researchers will determine if these known gene variations are also related to the three mental processes, as well as the brain functioning and anatomy associated with them.
The participants will come from a longitudinal study, which began with a sample of 306 participants when they were enrolled in preschool in the early 1970s. The ability to pursue long-term goals in the face of immediate temptation was assessed once every decade since the original testing. Participants have now reached their late 30s and early 40s, and information about their life-outcomes, such as their occupational, marital, and physical health, and mental health status are becoming available. In the proposed project, we will study two groups of people in this longitudinal study. Individuals in one group have displayed high levels of self-control consistently over four decades, and those in the other group have consistently displayed self-control abilities well below the average of the cohort. By comparing these groups, we hope to learn the extent to which basic mental processes, brain functions and anatomy, and genetic variations are related to self-control. What we learn from this study may lead to a more precise understanding of the mechanisms that enable self-control, and may provide a foundation for future intervention to facilitate people's efforts to exert self-control.
