Tuesday, May 24, 2016

Kids Want to Learn About Kinds, Not Individuals

By the time you are an adult, you know a lot about the world.  You know that dogs bark, that computers allow you to communicate with people around the planet, that airplanes fly you from city to city, and that water boils at 100 degrees Celsius.  You also know a lot about individuals you have met.  You know your mother’s maiden name (which is handy when you need to open a bank account).  You know your best friend’s favorite color, the toy your aunt’s dog likes to play with, and exact way you need to unlatch the gate at your grandparents’ house. 

Your knowledge about individuals is useful for helping you to interact with specific situations in the world.  Knowing your best friend’s favorite color can help you buy a gift for her birthday.  Your knowledge about kinds of things (like dogs in general) can help you to predict what you should expect when you encounter a new dog.  Ultimately, you need to learn information about kinds of things in the world as well as information about the specific individuals you encounter.

An interesting paper by Andrei Cimpian and JoAnn Park in the February, 2014 issue of the Journal of Experimental Psychology: General examined what 4- and 5-year-old kids do when they are given a choice to learn about a particular individual or a kind in general.  

In one experiment, children sat with an experimenter who brought pictures of several unfamiliar animals (like a pangolin and a tarsier).  For half the children, the experimenter said that she was an expert and knew a lot about these animals.  For the other half of the children, the experimenter said she did not know much about the animals, but could guess some facts about them.

The experimenter showed a picture of an animal and said that she could tell the child a fact about that particular animal or about that kind of animal in general.  Children would let the experimenter know what kind of fact they wanted, and they would be given a fact.  Children were able to learn 3 facts for each picture and there were 4 pictures for a total of 12 trials.

When the experimenter said she was just guessing, children had no preference for getting facts about individuals or kinds.  This result makes sense, because the facts the child is getting are equally useless.  When the experimenter said she knew a lot about the animals, though, the children wanted information about the kind of animal much more often (64% of the time) than they wanted information about the individual.

One possibility is that children just want information that applies to more individuals, and that is why they choose to get facts about the kind.  In a second study, some children were given the chance to get a fact about the animal pictured or about several other specific animals that were not in the picture.  In this condition, children had no preference for getting a fact about one animal or a fact about several.  

Finally, a third study repeated the first experiment with familiar animals (like sharks, ants, and crickets).  Once again, children had no particular preference for facts about individuals or kinds when the experimenter said she didn’t know anything about the animals, but preferred to get facts about the kind in general when the experimenter said she was an expert.

This result suggests that when young children are around people with expertise, they want to learn about categories of objects.  This bias helps them to learn facts that will help them to deal with new things that they encounter.  This finding also argues against another way that children could learn about the world.  Children could learn lots of facts about individuals and then try to generalize those facts to apply to all members of the kind.  Instead, children prefer to learn about facts that apply to the kind. 

Wednesday, April 27, 2016

People Differ in Their Ability to Suppress Memories

Your ability to recall a word or event involves mechanisms that enhance the item you want to remember and suppress competitors.  It is like a bunch of 6-year-olds trying to be picked for the kickball team.  The kids who jump the highest and shove the other kids hardest are the ones who are selected.

Psychologists use the word inhibition to refer to the suppression of items in memory.  The inhibitory mechanisms in the brain involve circuits in the frontal lobes.  

A fascinating observation over the past decade is that these inhibitory mechanisms in the brain can cause subtle variability in people’s heart rate through the vagus nerve.  If you measure someone’s resting heart rate and measure the amount of variability in the time between beats, that variation may serve as a marker of the strength of people’s ability to inhibit information in memory.

An interesting paper by Brandon Gillie, Michael Vasey, and Julian Thayer in the February, 2014 issue of Psychological Science explored this possibility.  

They used a memory test called the Think/No Think procedure first developed by Michael Anderson and his colleagues.  In this procedure, people learn a list of associations between words.  The list might include items like “tape-radio.” 

After practicing these associations 3 times, the Think/No Think procedure begins.  The first word of a pair (tape) is presented in green or red (or is not presented at all).  If it is presented in green, then people are instructed to think about the associated word for 4 seconds.  If it is presented in red, then people are instructed to avoid thinking about the associated word for those 4 seconds.  This procedure is repeated 16 times, so that people get a lot of practice either thinking about the association or not thinking about it.  

There are two tests of recall.  People see the first word of the pair and are asked to recall the second.  In a second test, they see the first word of the pair and the first letter of the second word and are asked to recall the second word. 

Finally, all participants had their heart rate collected using an electrocardiogram (ECG).  The ECG output was analyzed to determine the variability from beat-to-beat.

The standard finding with this procedure (which is also obtained in this study) is that (on average) people recall about 10% more of the associations when they see them in the Think condition than in the No Think condition.   

The group of participants was split into one group with relatively high variability in heart rate and a second group with relatively low variability in heart rate. 

Having low heart rate variability is associated with having low inhibitory control in memory.  That group showed very little difference between the Think and No Think conditions of the study.  They remembered the associated words equally well regardless of whether they were instructed to think about them or not to think about them.

Having high heart rate variability is associated with high inhibitory control.  That group showed a big difference between the Think and No Think conditions.  They remembered many more words when they were encouraged to think about them than when they were encouraged not to think about them.

The ability to inhibit unwanted items in memory is valuable.  Research suggests that this ability degrades with age, which is one reason why older adults often have trouble with memory.  So, having a physiological measurement that relates to this degree of inhibitory control is useful.
As valuable as the ability to inhibit information can be, it is important to recognize that the No Think condition does not eliminate people’s ability to recall the associated words.  Creativity requires being able to think about information that does not seem obviously related to the current situation.  Juxtaposing different information sources is a great way to look for a novel solution to a problem.  As a result, we want to have good inhibitory mechanisms, but not ones that work too well.

Monday, April 18, 2016

Beliefs About Time Affect Savings

It is hard to save money, because we are wired to prefer to do things that are good for us in the short-term over those that are good for us in the long-term.  No matter how much we believe that our future self might want to buy a nice car, send our kids to college, or eat after we retire, there are always shiny things that we would like to buy right now that seem to have a priority over our future.  

So, how can we help people to save more money?

A fascinating paper by Leon Tam and Utpal Dholakia in the February, 2014 issue of Psychological Science suggests that people’s beliefs about time may have a big impact on how much they save.

The dominant way that many people (particularly from Western cultures) tend to think about time is as a line.  Individuals occupy a point on that line that is the present.  Behind them is the past, and ahead of them is the future.  Because the future is far away, many approaches to help people save more money are designed to make people feel like the future is nearer to the present than it seems.  The idea is that when people realize that they have to help our future selves, they will be more likely to put away money to help them achieve their future goals.

These techniques often fail, however.  People recognize that their future selves may need help, but they are also optimistic that they will be making more money in the future and so they will be in a better position to save money later than they are now.

Tam and Dholakia point out that people also think about time in terms of cycles.  People know that the days of the week repeat, and that the seasons come each year.  When people focus on these cycles, they may realize that their lives don’t change much from cycle to cycle.  Consequently, if people don’t save money now, why should they believe that they will be in a different situation the next time this cycle happens?  The researchers argue that getting people to focus on the cyclic nature of time may get people to increase the amount they save, because they realize that the future will not be that much different than the present.

In one study, adults between the ages of 19 and 55 were placed in one of three experimental conditions.  

One group was told to think about time as a cycle and to recognize that life’s cycles repeat themselves.  They were told that if they do not save money now, they are unlikely to be in a different situation the next time this cycle came around.

A second group was told to think about time as a line.  Their goal was to save money to put their future selves in a better position to achieve their goals.  

A third group got no specific instructions about time.

Then, the participants predicted how much money they would save over the next two weeks.  Participants were then contacted after two weeks and stated how much they had saved in that period.

Participants in the control condition predicted they would save $133, and actually saved $81.  Those told to think about time as a line did not do much better.  They predicted they would save $140, and actually saved $118.  The group given instructions to think about time as a cycle did much better.  They predicted they would save $233 and they actually saved $216.  

Another study by these authors extended the work in two ways.  First, participants were either told to think of time as a line or as a cycle.  They made predictions both for how much they would save this month and also how much they would save a year from now.  Participants told to think of time as a cycle predicted they would save more this month than those who were told to think of time as line.  This replicates the previous study.  However, those told to think of time as a line predicted they would save more money a year from now than those who were told to think of time as a cycle.  That is, participants who thought of time as a line were more optimistic about their future ability to save money than those who thought of time as a cycle.  

Finally, everyone was asked questions about their ability to make plans to save money.  The participants asked to think about time as a cycle exhibited more confidence in their plan to save money than those asked to think about time as a line.

What does all of this mean?

We are often optimistic about what the future holds.  In the future, we believe that we will make more money, be better at resisting temptation; we assume we will eat better and exercise more often.  In reality, though, the future is typically much like the present.  There are always temptations to spend money, eat too much and skip exercise.

Focusing on the cycles of life helps people to be more realistic that the future will be like the present.   Achieving future goals requires acting now. 

Wednesday, April 13, 2016

Young Infants Learn By Doing

The brain is an extraordinarily complex organ that we are struggling to understand scientifically. To help us understand the way the brain works, we often use the most complex machines of an era to give us insight into what the brain is doing.  And starting in the 1950’s, the most complex machine we had was the computer.  

One influence of this computer metaphor for the mind is that it has emphasized the information that is processed in the brain over the relationship between mind and body.  After all, computers have poor bodies.  They have a keyboard and mouse as a sensory system and a display and internet connection as ways of acting on the world around it.  As a result, most research in psychology focuses on how the brain processes particular kinds of information without much focus on how the body influences that thought.

There are some streams of research that buck this trend.  In research on adults, there is work on situated cognition that explores how the environment affects the way people think.  There are also studies in embodied cognition that examine how body and mind interact.

Over the years, there has also been work on how the body influences learning in infants and children.  In my last blog entry, for example,  I talked about how experience moving influences children’s curiosity about heights.

A fascinating paper in the February, 2014 issue of Child Development by Sarah Gerson and Amanda Woodward examines how 3-month-olds learn about other people’s goals from their own actions.

If you have ever spent any time with a 3-month-old, then you know that they are not particularly coordinated.  Jessica Sommerville, Amanda Woodward, and Amy Needham developed an ingenious method for looking at actions in 3-month-olds (reported in a paper in the journal Cognition in 2005).  They attached mittens with Velcro on them to infants’ hands.  Then, the infants could reach out and move toys that also had Velcro on them.

In Gerson and Woodward’s study, all of the infants had a chance to sit with the toys for a few minutes without the mittens.  Then, some infants had the mittens put on, and they reached out and played with the toys for a few minutes.  For these infants, playing with the toy generally meant moving it back-and forth across the table.  A second group of infants was matched with the infants from the first group.  For each infant in the second group, the experimenter mimicked the actions of the infant using Velcro gloves, so that this infant got to watch something similar to what the first infant did.  That provides a control condition in which the infants are exposed to the actions without actually performing the actions themselves.

After this initial exposure, infants were tested.  It is hard to test 3-month-olds, because they cannot speak or understand much language.  Instead, researchers typically use a looking procedure.  

In this study, the two toys that were used in the first part of the study were placed on a stage.  A gloved hand reached out and picked up one of the toys.  This event was presented several times until the infants stopped looking at it.  This decrease in looking time is called habituation and is used as a measure that the children can predict what is going to happen.

Then, the positions of the two toys were switched.  So, the one on the left is now on the right and vice versa.  Now, two types of test trials were given.  In one type of test trial, the hand reached out and grabbed the toy that was now on the left.  In this case, the hand performed the same action, but the outcome was different.  In the other type of test trial, the hand picked the same object that it selected before.  In this case, the movement was different (because the hand had to reach all the way to the right), but the outcome was the same (because the same object that was touched earlier was selected again).  

The experimenters measured how long infants looked at each type of test.  The longer infants look, the more interested they are in that outcome, generally because that outcome is different from what they expected.

The infants who watched someone else acting on the toys did not look reliably longer at either type of event. Those infants who acted on the toys themselves looked for a longer time at the event with a different outcome than at the event with the same outcome.  That is, by playing with the toys, infants seemed to learn that other people often direct their actions at particular outcomes rather than just making particular movements.

The infants learned something very specific from this experience, though.  A third group of infants played with the toys using the mittens, but then the test trials involved a different set of toys than the ones they played with.  This group also did not look reliably longer at either type of test event.  That is, the infants learned only about outcomes involving the specific toys they played with.

What does all of this mean?

One way that infants learn about what other people want to do is by learning about how they perform actions in the world.  As they learn that their actions can be directed toward particular outcomes, they also learn that other people may act to bring about particular outcomes.    

However, it also appears that this learning is very conservative.  That is, infants start by learning about their interactions with particular objects.  It is valuable to keep from generalizing too far from early experience, because there are likely to be many exceptions to the early rules that infants learn.

More broadly, this research demonstrates the importance of acting on the world when learning.  Too often, even adults try to learn passively by listening to others and reading superficially.  It is important to engage with the world when learning rather than just treating the process of learning as if we were computers that were being fed information.

Monday, April 4, 2016

Are Infants Afraid of Heights?

When I was in college, I worked at a lumberyard.  One day, the boss asked me to climb to the second level of a storage barn at the back of the property and do an inventory on the 4’ by 8’ sheets of paneling in bins at the top of the barn.  There was a one foot ledge in front of each bin, and so I had to sit on that ledge, about 10 feet off the ground, and lift each sheet of paneling in the bin to count them all.  After the second bin, I slid over to the ladder, climbed down, and gave up.  I was simply too scared of the drop to continue.

When do people become afraid of heights?

This question was discussed in a paper in the February, 2014 issue of Current Directions in Psychological Science by Karen Adolph, Kari Kretch, and Vanessa LoBue. 

If you are familiar with research in developmental psychology, then the answer might seem obvious.  In the 1960s, there was a lot of research done on the visual cliff, which was developed by Eleanor Gibson and her colleagues.  The visual cliff involves a ledge with a checkerboard pattern.  There is glass at the dropoff of the ledge, so that infants see the cliff, but do would not be hurt by stepping onto it.  Infants who have first learned to crawl climb right out onto the cliff.  Those with a few weeks of movement experience stop at the edge.

It seems straightforward to say that the infants stop at the edge, because they are afraid of falling.  And for years, that was the standard way of talking about infants’ performance on the visual cliff.

The problem is that infants don’t really display a true fear reaction when they get to the edge of the cliff.  They don’t climb out onto it, but they do spend a lot of time peering over the edge.  They reach out and explore the space.  They do not display fear on their faces.  They do not cling to their parents. 

Infants of that age can display fear.  For example, when infants of that age are approached by strangers, they do cling to a familiar adult, have an increase in heart rate, and have facial expressions and make noises that are fearful.  So, infants can feel fear, they just don’t seem to exhibit that fear to the cliff.

Instead, infants quickly discover that heights create situations in which something can be learned.  For example, infants learn about ramps and stairs.   Over time, they learn which stairs can be climbed up and down and which are too high.  They learn what kinds of ramps are too steep to climb down.  Work by Karen Adolph and her colleagues even demonstrates that infants react differently to ramps depending on whether they are wearing a vest with lead weights in it (which makes a ramp harder to descend) or with feathers in it (which has little effect on their movements). 
Early on, then, infants are curious about heights, but not fearful.  They recognize that they should not immediately dive over a cliff, but they also spend time in that environment trying to learn what they can and cannot do. 

Eventually, of course, many children do display some fear of heights.  Some children may fall and learn their fear in that way.  However, just watching someone else fall or even something else fall from a height may be enough to help children realize the dangers of falling from heights.  But, this fear does not kick in until after children have had some opportunity to explore their environment.

Thursday, March 24, 2016

Mental Energy and Physiological Energy

When we talk to other people about achieving goals, we often speak in terms that relate to energy.  We think of ourselves as getting energized to get to work.  Psychologists talk about the energy that is related to achieving goals as arousal.

Is this mental energy just a metaphor? That is, are these goals just energized in the mind, or does that energy translate to physiological energy in the rest of the body?

This question was explored in a paper in the February, 2014 issue of Personality and Social Psychology Bulletin by Timur Sevincer, Daniel Busatta, and Gabriele Oettingen.

In one study, they looked at a method that Gabriele Oettingen and her colleagues have used many times in the past to study the arousal of goals.  Their works shows that a good way to energize a goal is to do a mental contrast.  First, think about the desired future that you want to achieve.  Then, think about where you are right now related to that goal.  For people who believe the goal can be achieved, this mental contrasting is an effective way of energizing the goal.  But, for people who believe that the goal is impossible to achieve, this kind of mental contrasting actually makes people less interested in achieving the goal. 

In this study, the researchers linked this kind of mental energy to physiological energy using changes in systolic blood pressure.  In one study, college students came to the lab and had a baseline blood pressure measurement.  They also did a task where they squeezed a metal hand grip and the researchers measured how long they could hold the hand grip closed.  This task is often used in psychology experiments as a measure of physical effort. 

After that, participants were told that they were going to write a fictitious graduate admissions essay.  They rated how well they thought they would do in this task.  That was a measure of their belief in whether they would succeed.

Next, some participants did a mental contrasting exercise in which they thought about an aspect of themselves like self-confidence and focused first on how writing the essay would make them feel in the future.  Then, they thought about that aspect in themselves right now.  A second group thought only about the future.  A third group focused on unrelated interactions with a teacher.

After these exercises, participants had a second measure of systolic blood pressure.  They also squeezed the hand grip again.  Participants did not actually write an essay.
Participants in the future and control conditions showed no particularly strong pattern of results.  Their systolic blood pressure was not strongly influenced by their thoughts, and there was no major change in their ability to squeeze the hand grip.

The participants in the contrasting condition showed an interesting pattern, though.  When they thought the task was not achievable, their systolic blood pressure went down.  When they thought it was highly achievable, then their systolic blood pressure went up.  The same pattern was observed with the hand grip.  Those who thought the task was not achievable held the grip closed for a shorter period of time than they had in the baseline condition, but those who thought it was achievable held it for a longer period of time. 

This study suggests that getting mentally energized to achieve a goal creates physiological energy.  That energy is reflected both in a change in blood pressure as well as an increased ability to perform a physical task.

Perhaps it should not be so surprising that mental energy creates a physiological response.  The brain controls bodily action, and many of our goals require physical reactions.  In the modern era, though, a lot of our mental work is done without much physical activity, and so it is easier to believe that the goals engaged by the brain are contained primarily in the brain. 

Thursday, March 17, 2016

Control and Health

At any given moment, you may feel as though your ability to succeed in the world involves some combination of your own efforts and factors that are out of your control.  Starting about 50 years ago, psychologists began to explore the relationship between people’s beliefs about the amount of control that they have in a situation and their behavior.  

This work suggests that people who believe that their efforts drive success in situations tend to work harder and to do more positive and healthy things than people who believe that factors outside their control are affecting outcomes.  Essentially, when you believe that your own actions matter, then you work to create the outcomes you desire.  When you believe that your actions will not have much of an impact on the future, then you do not put in much effort.

A key concept in this work is locus of control.  People with an internal locus of control believe that they are the authors of their destiny.  People with an external locus of control believe that circumstances control their future.  Much of the work on this idea has focused on locus of control as a personality trait that is relatively stable over time.

An open question is whether there are variations within individuals in locus of control that also affect the way they act.  This question was addressed in a paper by Holly Ryon and Marci Gleason in the January, 2014 issue of Personality and Social Psychology Bulletin. 

They had a sample of pregnant couples fill out a daily survey for three weeks.  The women were in their last trimester of pregnancy.  Their non-pregnant partner also participated.  Pregnant couples were used (in part), because they are likely to experience a lot of stress and changes in health on a daily basis.  Most people’s lives are a little less adventurous than those of pregnant couples as they approach their due date.

Each day, they filled out a number of scales. One measured locus of control (with questions like “Today I was able to deal with my problems” and “I feel that I have control over the things that happen to me.”).  They also filled out measures of anxiety and depression.  They reported whether they exercised and ate a healthy diet and also any negative health symptoms they experienced.  They also reported the hassles they experienced that day (including health problems, car problems, financial problems, and issues with their partner). 

One set of analyses demonstrated that the daily hassles people experience affect people’s perceived locus of control.  The more hassles, the more that they felt that circumstances controlled their lives.  The anxiety they experienced that day also affected their locus of control. 

Daily differences in locus of control then predicted behavior and symptoms.  For both the pregnant partner and the non-pregnant partner, the more they believed that their actions controlled the future, the more that they engaged in healthy behaviors like eating well and exercising and the fewer negative symptoms they experienced.

This work extends previous studies by demonstrating that even day-to-day changes in your beliefs about your own effectiveness in the world influence your behavior.  On those days when you feel like you are in control, you act in healthier and more proactive ways than when you believe that the world is controlling you.  When you feel like you have no control, it can be valuable to engage with other people and let them help to motivate you to act in healthy and productive ways.