Think about a time when you did something that you really regretted…
Now try to stop.
When we think about something that happened to us in the past, the emotions that were originally elicited by that event come rushing back. Thinking about a past event repeatedly, or ruminating (a term which also means to “chew the cud”… perhaps you can see the link here) can cause emotional distress, and people who ruminate a lot are at risk for experiencing mental health problems such as depression and anxiety. But why do some people ruminate so much? Some argue that these people may be less mentally “flexible”, even when the content they are dealing with is not personal or emotional in nature, and this leads them to have difficulty letting go of things that happened in the past. But if the consequences of rumination are negative, why is it a common problem? Perhaps rumination has an upside….
In line with the “mental inflexibility” theory, a recent study showed that people who ruminate a lot make more mistakes when they have to switch back and forth between simple tasks, relative to those who ruminate less often (Altamirano et al., 2010). However, ruminators also made fewer mistakes when they had to maintain their focus on a single task. The differences probably weren’t due the ruminators actually thinking about the past while they were trying to do the tasks – after all, if that were the case, these people should have performed worse across the board.
So people who ruminate a lot appear to be mentally inflexible – they have difficulty shifting from one task to another, so once they start thinking about a past event, they can’t put this event out of their mind and focus on the present. If this inflexibility really does causes people to ruminate more, then helping these individuals to become more mentally flexible might help them learn to ruminate less (and if you are still thinking about that thing that you regret, you might be able to benefit from this too). On the other hand, the discovery that people who ruminate a lot are particularly good at focusing on one task suggests that rumination can have an upside. Specifically, ruminating a lot might help these people develop the ability to maintain their focus on one thing for long periods of time. Another possibility is that the ability to focus helps people maintain their concentration on unresolved events from the past, for better or worse. Either way, that fact that rumination is associated with a skill that is generally useful and adaptive might help to explain why it is such a common experience, despite the fact that it can lead to emotional hardship.
Altamirano LJ, Miyake A, & Whitmer AJ (2010). When mental inflexibility facilitates executive control: beneficial side effects of ruminative tendencies on goal maintenance. Psychological science : a journal of the American Psychological Society / APS, 21 (10), 1377-82 PMID: 20798398