Tag Archives: statistics

Statistics and physiology: why getting it right matters

With recent advances in brain imaging and gene mapping we have significantly more data to help us understand human behavior. For example, we can see how folks with PTSD react to triggers using SPECT scans. We can understand how some folks have genetic markers that indicate a propensity for certain kinds of addictive behavior.

Enter this news story on NPR about one researcher who discovered he had the brain scan of a sociopathic killer–the very kind of people he was studying.

It is essential that we understand how to interpret these kinds of studies that often make the news. I am not an expert in brain scanning but let’s review a simple statistical principle. If you evaluate that 100% of people who have a particular problem (in this case sociopathic murder) have a particular brain scan signature, what can you say about its application to the general public? NOTHING. You cannot say, yet, that having that brain scan signature puts you at risk for becoming a murderer. What we need to know is whether or not that brain scan exists in the general public. I am willing to bet that if we did a large-scale study, we would find that 99% (maybe even higher) of those with a similar signature would NOT be killers. Thus, we cannot predict anything on the basis of the scan.

A similar (non) relationship exists between childhood abuse and becoming a child abuser. Yes, when we research pedophiles we find a high correlation between childhood sexual abuse and those who are in prison. But, when we look at the general public and victims of sexual abuse, we find that less than 1/2 of 1% go on to abuse others. Thus, abuse victims are not likely to become abusers.

However, these studies are not meaningless. In the case of the underactive frontal/orbital lobe, we do see certain features often present in individuals with ADHD: impulsivity, emotional lability, ego-centrism, lesser ability to learn from mistakes, difficulties in planning and forethought, etc. Rather than try to predict big events (like murder), we might use these kinds of studies to understand the common experiences and activity of those with a particular signature. This does not absolve people of responsibility or suggest they cannot make changes in how they operate. But, it might help us grow in understanding that what might be easy for one person may be more difficult for another. Just like we would want to give someone with dyslexia more time to read and comprehend a piece of literature, we might want to make some allowances for someone with a quiet frontal lobe.

It might mean that we understand that everyone thinks thoughts that ought not be repeated but that some have a harder time not saying it. And in the case of those “some”, we might be more willing to cut them slack even while we call them to account for saying what they say.

Leave a comment

Filed under counseling, Psychology

Decisions by the numbers or by the gut?

We all make decisions every day. And most of us like to think that our decisions are based on adequate data. We consider going to college or grad school. Which school has the best degree, best profs? Which will give be the best options post graduation? We consider getting married. Will ____ be a good spouse? We consider buying a car. Should I buy a Toyota because their history of longevity and safety are well documented or do I skip them because of the gas pedal situation? We consider which counselor to use for our problems. Do I choose a christian or someone who is board certified (I know, I know, they can be both)?

We make decisions all the time but they are NEVER based on enough data. This is where faith or our gut is involved. For example, I didn’t know my wife would be the best wife to have. Well, I’ll tell you I did but I didn’t.

What I am aware of is how we have so much more data available to us these days to make our decisions. At times, the data can be helpful but it can also deceive us into thinking that we have more control over the outcome.

Consider these counseling related examples:

1. Home Sleep study devices. I saw an ad for a radio alarm clock sized device that records your time to sleep, your REM time, your number of awakenings and your wake point. Assuming the device works, you can really track your sleep in a much more accurate way (rather than just going by how it felt). There might be some benefit to this, especially if it helped you be more consistent in your bedtime rituals. But, data doesn’t stop anxiety nor does it alter sleep apnea.

2. Scales. I have a new scale at home that gives me all sorts of data. So, I weigh myself more frequently just to see what changes. Of course, it has yet to change my eating habits nor really tell me much that I didn’t already know.

3. Pop Psych treatments. I suppose some will challenge me here on this category. But there are a number of popular forms of treatments or assessments out there that purport to pinpoint your problem, remove your problem, or illustrate the healing you just received. Each of these forms of treatment have stories, anecdotes, even statistical data. But few have been researched in controlled studies. So, the data may be accurate and yet meaningless to you at the same time. These interventions may well be useful but often the promise outstrips what is really known at the present time.

I might sound like I’m down on data. I’m not at all. We have some wonderful tools now to track information. Data can give us direction. But, in the end, we have to decide and there are other kinds of “data” that we use to make these decisions: feelings, recent experiences (our own or others), first reactions, amount of energy, hope, etc. Let us not deceive ourselves that we truly live by the numbers.

Leave a comment

Filed under Cognitive biases, Psychology, Uncategorized