Tag: cognition

Reasoning and problem solving question

A recent reading quiz question in the area of problem solving confused a student. The student wrote:

Dr. Leighton,
Could you please explain to me why this is wrong? I was confused by the book, because it does say that you can have a “valid but incorrect conclusion” if the “premises use terms inconsistently or ambiguously”, which the term environmentalist is very broad and could be considered ambiguous in the question, so I am not really sure what the correct answer is.

This is a good question. Here is the question and answers from the quiz:

Mr. Smith is running for Congress. Alejandro does not know much about Mr. Smith, but he has heard that Mr. Smith is an environmentalist. Because Alejandro cares about the environment, he votes to send Mr. Smith to Washington. After the election, Alejandro finds that Mr. Smith does not act like an environmentalist, and he regrets having voted for him. Alejandro’s mistake was forgetting that:

Question
Mr. Smith is running for Congress. Alejandro does not know much about Mr. Smith, but he has heard that Mr. Smith is an environmentalist. Because Alejandro cares about the environment, he votes to send Mr. Smith to Washington. After the election, Alejandro finds that Mr. Smith does not act like an environmentalist, and he regrets having voted for him. Alejandro’s mistake was forgetting that:
Answers
Selected A. a conclusion is true only if the premises are true
B. a conclusion can be valid without being true
C. premises with ambiguous terms lead to incorrect conclusions
D. both B and C

The student thought both B and C should be correct. The correct answer is A. Why? Here’s what I wrote to the student:

This is a good question. Lets walk through the example.

Remember that a syllogism has a premise and conclusion. In this case, what’s the premise and conclusion?

I think the premise is that Mr. Smith is an environmentalist. I think the conclusion is that Mr. Smith will act like an environmentalist.

I don’t think that “environmentalist” here is ambiguous. What I think the issue is whether the premise is correct. So, what is the basis for the premise?

The basis for the premise is what Alejandro heard about Mr. Smith. That’s a pretty suspicious basis for the premise – so I think the weakest part of the example is whether what Alejandro heard about Mr. Smith is true.

The evidence that Mr. Smith does not act like an environmentalist indicates that the conclusion is incorrect, and thus the premise is not true. Thus, the conclusion is only valid if the premise is true.

Does that help?

Lets use another example.

Instead of “environmentalist” we substitute something more ambiguous: how about “can fly?” Then we can get something like:

Alejandro does not know much about Mr. Smith, but he has heard that Mr. Smith can fly. Because Alejandro thinks it would be awesome to have someone with superhuman powers in congress, he votes to send Mr. Smith to Washington. After the election, Alejandro finds that Mr. Smith doesn’t have feathers and has never been seen flying around the capitol, but instead is just an airplane pilot, and he regrets having voted for him.

Now we have a conclusion (Mr. Smith has superhuman powers) that is based on an ambiguous premise (Mr. Smith can fly).

Make sense?

The benefits of heuristics and impulse decisions

The NY Times has a very good article illustrating the benefits of heuristic decision making processes over algorithmic ones. In this case, the author is talking about how long he spends making purchasing decisions. This is very familiar to me.

the time I spend overanalyzing prices will cost me way more money, in the form of opportunity costs and cognitive drain, than I could ever hope to save.

We generally believe that the best decisions come from examining all options and making a decision based on all available evidence. But, this evidence gathering comes at a cost: in this case, the personal resources (financial and otherwise) that are spent making the decision.

We need to accept that we can’t always make the best decisions, but we can make good ones. Generally, good decisions will make the most of our resources and free us to move on to other important things.

In cognitive complexity theory, one of the things we drive home is the idea that the situation might determine the maximum amount of complex thinking we can apply to a problem. For example, consider how the US might respond to another massive terrorist attack (or attack from another nation). When deciding whether to go to war or not, we can use more complexity if making a decision in the weeks or months before we are under attack, but in the case of a surprise attack, that kind of complex thinking could take lots of time and resources, two things we are desperately short of in the midst of an attack. In that case, taking the time and resources necessary to consider all the options (high complexity) might result in a slow response and the likelihood of more attacks, versus using heuristics and considering fewer options (lower complexity) which might allow a rapid response to avert another attack.

Link to the article: Getting Over Cold Feet: The Case for Impulse Buying – NYTimes.com.

Diane Halpern on Hyperpartisanship

One of the authors of the book we are using in Introduction to Psychology this semester is Diane Halpern. She recently won an award from the Association for Psychological Science, and gave a talk on cognitive psychology research on hyperpartisanship. Here’s a link: Link

A cognitive scientist, Halpern called on American citizens to adopt several practices that can ease the ideological divisions that plague the country today. She pointed to 70 years’ worth of research showing that cooperation and interaction are key ways to minimize prejudice and improve intergroup relations.

Ego depletion, glucose, and self-control

The excellent science writer John Tierney has an essay in the NY Times Magazine about the effects of ego depletion—the idea that self-control is a limited resource that can be depleted the more we use it. The article, which is excerpted from a book he wrote with the social psychologist Roy Baumeister, specifically addresses the fatigue that sets in when we’re faced with choices, which impedes our ability to make good decisions later.

The most interesting part for me was the implications for poor people who have to make choices all day long in terms of how to allocate limited financial resources. We often associate low socioeconomic status with some kind of willpower failure, and consequently make a dispositional attribution: they are weak people, and so they make bad choices. But in fact, this can be a product of the situation: the many difficult choices they have to make all day long.