The unpredictable past: spontaneous autobiographical memories outnumber autobiographical memories retrieved strategically.

Involuntary autobiographical memories are spontaneously arising memories of personal events, whereas voluntary memories are retrieved strategically. Voluntary remembering has been studied in numerous experiments while involuntary remembering has been largely ignored. It is generally assumed that voluntary recall is the standard way of remembering, whereas involuntary recall is the exception. However, little is known about the actual frequency of these two types of remembering in daily life. Here, 48 Danish undergraduates recorded their involuntary versus voluntary autobiographical memories during a day using a mechanical counter. Involuntary memories were reported three times as frequently as voluntary memories. Compared to voluntary memories, they were associated less with problem solving and social sharing and more with day dreaming, periods of boredom, no reasons for remembering and predominantly came to mind during unfocused attention. The findings suggest that involuntary recall is a typical way of accessing the personal past.