Not Another Excuse!

NBC published this story about research at Harvard claiming that people are more dishonest in the afternoon than in the morning.  They propose that self-control is a finite resource; we use it up throughout the day.  We get worn out from trying to be good making us more likely to give in to temptation later.  With obesity and retirement insecurity among the major crises, what America doesn’t need is another excuse for behaving poorly in the dimension of discipline.

Before getting too excited about this too-good-to-be true permission to blame the time of day for failings, it’s best to ask a few questions about the research.

Two Harvard professors tested 62 undergraduates who signed up for either a morning or an afternoon ethics class.  They showed the students 100 squares that had been cut in half and marked with dots.  Asked to vote which half appeared to have more dots, they were also told that voting for the right half paid more than voting for the left -- their perception only, without regard for accuracy.  This condition set them up to be able to cheat and get away with it.  Participants in the afternoon indicated more frequently that dots appeared on the right side than those in the morning sessions.  Another test gave them a choice between reading more challenging material or a lighter magazine article.  A greater number from the afternoon class tended to take the easier assignment.

Their recommendation is that people should schedule more challenging work for the morning, especially if it has a moral component.  Get it done before your energy for honesty and resisting temptation dwindles.

How, though, can they apply this to everyone?  Surely Harvard students are not representative of the entire population.  This is called convenience sampling and is usually frowned upon when doing serious science.  In any case, would groups of 31 would be an adequate sample size?  More information is needed.

Furthermore when comparing one group to another, every effort should be made to control for differences that might influence the outcome.  Do those who signed up for the afternoon classes have the same characteristics as the morning students?  Is it possible that the morning students were a little more motivated, opting to attend class rather than sleep in?  What background and habits did they bring with them to class?  Were they equally balanced on other differences such as sex, age, and economic background?

This story leaves a lot of questions unanswered.  Critical thinkers look for answers to those questions before accepting conclusions and recommendations at face value.