Wednesday, August 29, 2018

Conflicting Goals Can Make You A Better Decision Maker

We tend to think of conflict as the enemy of good decision making.  We dread situations that involve difficult choices.  Indeed, studies by Amos Tversky, Eldar Shafir, Ravi Dhar, Itamar Simonson and their colleagues suggests that people will actually avoid making decisions that are difficult.  When given a choice between selecting one of two options that require making a difficult tradeoff (for example, selecting apartments that differ in size and commute time), people prefer to put the decision off until later rather than addressing it right away.
An interesting paper by Jennifer Savary, Tali Kleiman, Ran Hassin, and Ravi Dhar in the February, 2015 issue of the Journal of Experimental Psychology: General suggests that there may also be an upside to experiencing conflict. Specifically, they suggest that when people have two conflicting goals that they are grappling with, that makes them likely to think carefully about choices in order to resolve the conflict.
In order to induce conflicting goals, participants did a lexical decision task in which they saw a series of letters and had to press one button of those letters formed a word and a second button if they did not form a word.  In the conflict condition, some of the words referred to a particular goal (such as being healthy, with words like fitness and active), and others referred to a second goal that conflicts with the first (such as indulgence, with words like decadent and indulge).  The control condition did not have conflicting goals embedded in the words that were part of the lexical decision task.  Tasks like this have been used in many previous studies to activate goals and to create goal conflict.
After this lexical decision task, one study gave people difficult choices (like a choice between apartments that differ in size and commute time) and asked people to select one of the options or to defer the choice until later.  Participants who were induced to feel a conflict between goals were actually more likely to choose one of the options rather than deferring the choice than people in the control condition who were not given a goal conflict.
In a second study, participants were given these choices using a computer system that tracked the amount of time participants spent making the decision and the number of features of the options they explored.  Participants induced to experience a conflict looked at more features and spent more time making the choices than those who did not experience a conflict.  This study also demonstrated that people were not aware of the goal conflict that was induced. 
One other study tested the idea that conflicting goals increase how thoroughly people process information about choices in a slightly different way.  Again, goal conflict was induced using the lexical decision task.  This time, though. The decision task involves selecting from among three options (say three different apartments).  One was very good on one dimension (it was large), but very bad on the other (it was far from work).  A second was bad on that first dimension (it was small), but good on the other (it was close to work).  A third was a compromise (medium in size, a moderate commute to work). 
Previous research suggest that when people don’t want to work that hard making a choice, they tend to select the compromise option so that they don’t need to figure out which dimension is more important to them.  If people really think carefully about the choice, then, they will be more likely to pick one of the extreme options rather than the compromise. 
Consistent with the other two studies, participants induced to have a goal conflict were more likely to pick one of the extreme options than people in the control condition who had no goal conflict. 
An interesting aspect of these studies is that the goal conflict that was induced was not directly related to the choices people were making.  So, the increase in depth of thought about the choices was caused by the presence of active goals that conflict, and not based on the activity of goals that were relevant to evaluating the options.
This research suggests that we experience two kinds of conflicts when making choices.  One conflict is between options that are about equally attractive and require tradeoffs among the features to figure out which is best.  These conflicts make it hard for people to choose.  Often, people prefer to defer the choice until later or pick an easy compromise option rather than resolving tradeoffs.
The second kind of conflict is one between incompatible goals.  These goal conflicts arouse the motivational system.  This arousal leads people to consider options more carefully, think about them more deeply, and ultimately helps people to make the tradeoffs that can make decisions difficult.

Monday, August 6, 2018

Sleep, Thinking, and Aging

I have written a few times about the influence of sleep on thinking.  High school students who stay up late perform more poorly in school the following day.  A lack of sleep may cause you to mix together different memories that did not occur together.  In young adults, sleep also affects the ability to learn new procedures. 
These benefits of sleep lead naturally to the speculation that sleep may help older adults avoid the cognitive declines that come along with aging.  One possibility is that older adults who suffer from sleep difficulties decline faster than those who don’t.  Another possibility is that regular sleep throughout life is associated with lower levels of problems.
A paper in the January, 2015 issue of Perspectives on Psychological Science by Michael Scullin and Donald Bliwise tried to sort out what is going on with sleep and aging.  The performed a massive meta-analysis.  A meta-analysis looks across the many published studies in an area of research in order to explore what really seems to be happening in an area.
There are many ways to study sleep and its effects on thought and aging.  Some studies use self-reports of sleep quality and measurements of cognitive performance.  Some of these self-report studies look at people of different ages.  Others are actually longitudinal.  They examine the relationship between the quality of sleep people get at one point in time and their performance later in their life.
Other studies use other measures of sleep.  Some studies use a device called an actigraph, which measures whether the person is moving.  (The Fitbit is a kind of actigraph.)  Long periods without movement are good (though not perfect) signals that a person is sleeping.  Still other studies measure physiological aspects of individuals like brain waves so that it is possible to tell both that people are asleep as well as the stage of sleep they are in.  Finally, there are experimental manipulations of sleep including sleep deprivation studies as well as studies in which people are randomly assigned to conditions in which they do or do not nap.
There are a lot of interesting findings in this paper, and it is worth giving it a read yourself for a more complete look at effects of sleep on thinking.  But here are a few highlights.
First, the relationship between sleep and improved thinking is strongest earlier in life and gets weaker later.  A good night’s sleep helps young adults to learn better the next day.  Sleep also helps young adults to consolidate (or solidify) memories from the day before more than it helps older adults.  Middle-aged adults show smaller effects of sleep on learning, and older adults show almost no relationship between sleep and learning at all. 
Sleep deprivation studies tell the same story.  Sleep deprivation generally hurts thinking performance, but these effects are much stronger in younger adults and small or even non-existent in older adults.  (This may explain why I can play the sax in a blues band until 2am on Sunday nights and still function at work the next day.)
Of course, part of the difficulty with studying sleep in older adults is that older adults generally need less sleep than younger adults, and the older adults who get the most sleep tend to be those who are sick and whose bodies are fighting off illness.
These results do suggest, though, that the amount of sleep that older adults are getting at that phase of their lives is not a cause of cognitive decline.
A particularly interesting result is that the quality of sleep in middle age influences cognitive health in old age.  The longitudinal studies are particularly helpful for this work.  When adults in their 40s and 50s get regular sleep and allow themselves to get the roughly 8 hours of sleep they need, they show fewer signs of cognitive problems like senile dementia when they are older.  Indeed, one of the studies in this sample measured sleep quality of adults in their 40s and followed up with them 28 years later.
Putting all of this together, then, it seems that sleep is most important for current cognitive performance in younger people, and that sleep plays less of a role in thinking as we age.  Sleep in middle-aged adults is still important, though, because good sleep habits in middle-age are associated with better mental health in old-age.