Human behavior is so interesting because our choices can sometimes defy reason. Take this example cited in Made to Stick about a study by Shafir and Redelmeier.
Students were given two options to spend their evening…
1. Attend a lecture by an author you admire who is visiting just for the evening.
2. Go to the library and study.
21% of students chose to study.
They then added another option…
1. Attend Lecture
2. Go to the library and study.
3. Watch a foreign film you’ve been wanting to see.
40% of students chose to study.
Unable to choose between two similar “good” options, the students settled for the safe choice of studying. They were uncertain to which “good” option would provide them with more value, but knew that studying would at least give them some utility. The addition of a contrasting option can alter the decision making process. Consumers tend to be more likely to choose between two “good” options if a third inferior option is added.
This comment was interesting. It’s incredible how you sometimes forget the fact you use marketing for people and not for statistics. =) Thank you.
Isn’t this actually a combination of the Similarity Effect and Default choice? Rather than make study more attractive, you’ve introduced a third option, similar to the lecture, which reduces the chance of the lecture being chosen. NOrmally this would then redistribute the above probability 40:40:20. But given study is the activity you would have to do anyway, it becomes a default option. Thereby redistributing probability between study (40%) and the two alternate options which are seen to be similar (and seen as one) to 60%). The probability has skewed because of uncertainty (indecision) in the alternate choice and when there is uncertainty, you go with the defaul (what you have to do anyway).