Please answer the above question before reading on . . .
I’m curious after reading Leif Nelson’s report that, based on research with Minah Jung, approximately 42% of the people they surveyed said they bought laundry detergent on their most recent trip to the store. I’m stunned that the number is so high. 42%??? That’s almost half the time. If we bought laundry detergent half the time we went to the store, our apartment would be stacked so full with the stuff, we wouldn’t be able to enter the door.
I think we buy laundry detergent . . . ummm, how often? There are 40 of those little laundry packets in the box, we do laundry once a day, sometimes twice, let’s say 10 times a week, so this means we buy detergent about once every 4 weeks. We go to the store, hmmm, about once a day, let’s say 5 times a week to put our guess on the conservative side. So, 20 trips to the store for each purchase of detergent, that’s 5% of the time.
Compared to us, lots of people must (a) go to the store very rarely, (b) buy really small containers of laundry detergent, (c) do the laundry all the time. I suppose that, all the time they lose by doing the laundry all the time, they save by not having to go the store every day. Some sort of cosmic balance.
P.S. Regarding their research, Nelson writes:
Minah and I could cheerfully use the same data to write one of two papers. The first could use a pervasive judgmental bias (18 out of 18 products show the effect!) to highlight the limitations of human thinking. A second paper could use the correlation (.95!) to highlight the efficiency of human thinking. Fortunately, this is a blog post, so I get to comfortably write about both.
I guess Nelson is joking here, but just in case he’s not: of course you should convey both results in your paper! One good thing about working in political science is that it does seem that our field has a good tolerance for complexity and ambiguity. It’s ok for us to write papers that convey mixed messages, if that is what we find. If it’s really the case that psychology papers need to have a single-minded focus, that’s too bad.
P.P.S. But before writing this paper I think the authors should do a within-person experiment (that is, asking the same people the same questions multiple times) with an aim toward decomposing their false-consensus finding (that recent detergent buyers overestimate the frequency with which people buy detergent, and recent detergent non-buyers underestimate that frequency) into two parts: the general frequency (we rarely buy detergent at the store so we, quite naturally, think of other people’s shopping habits as being in some general sense like ours) and the most recent behavior (it would seem more strikingly “irrational” if we make judgments about others’ purchases based on what we just did yesterday).