Like many medical studies, the Berlin Aging Study II (BASE·II) is based on a non·random "convenience sample" of self·recruited participants. To study processes of selectivity in BASE·II, we used an identical questionnaire to compare BASE·II with a large, representative reference study, the...

Delay of gratification (DoG) and delay discounting (DD) are behavioral measures of self-regulation and impulsivity. Whereas DoG refers to the postponement of gratification, DD involves the devaluation of a reward over time. Previous studies have demonstrated associations between paternal...