The researchers set out to determine whether there was a “first-toss Heads bias.” Meaning, when flipping a coin and the choices are presented “Heads or Tails,” there would be a bias towards people guessing “Heads” (because it was presented first). Through running their tests, they found something else that surprised them [Emphasis Added]:
Because of stable linguistic conventions, we expected Heads to be a more popular first toss than Tails regardless of superficial task particulars, which are transient and probably not even long retained. We were wrong: Those very particulars carried the day. Once the response format or verbal instructions put Tails before Heads, a first-toss Tails bias ensued.
Even in something as simple as flipping a coin, something where the script “Heads or Tails” is firmly engrained in our heads, researchers discovered that by simply switching the order of the choices, the frequency with which people chose one option or the other changed. That’s rather incredible and possibly has implications from policy to polling. However:
There is, of course, no reason to expect that, in normal binary choices, biases would be as large as those we found. In choosing whether to start a sequence of coin tosses with Heads or Tails, people ostensibly attach no importance to the choice and therefore supposedly do not monitor or control it. Since System 1 mental processes (that are intuitive and automatic) bring Heads to mind before Tails, and since there is no reason for System 2 processes (which are deliberative and thoughtful; see, e.g., Kahneman & Frederick, 2002) to interfere with whatever first comes to mind, many respondents start their mental sequence with Heads. However, in real-life questions people often have preferences, even strong ones, for one answer over another; the stronger the preference, the weaker the bias. A direct generalization from Miller and Krosnick (1998) suggests that in choices such as making a first-toss prediction, where there would seem to be no good intrinsic reason to guide the choice, order biases are likely to be more marked than in voting. At the magnitude of bias we found, marked indeed it was. Miller and Krosnick noted with respect to their much smaller bias that “the magnitude of name-order effects observed here suggests that they have probably done little to undermine the democratic process in contemporary America” (pp. 291–292). However, in some contexts, even small biases can sometimes matter, and in less important contexts, sheer bias magnitude may endow it with importance.
OK, so maybe these results don’t add too much to “government nudges,” but it can — at a minimum — give you a slight advantage (over the long haul) when deciding things by flipping coins with your friends. How?
Well, assuming that you are the one doing the flipping, you can say to your friend: “Tails or Heads?” (or “Heads or Tails?”) and then be sure to start the coin with the opposite side of what your friend said, facing up. A few years ago, Stanford math professor Persi Diaconis showed that the side facing up before being flipped is slightly more likely to be the side that lands facing up.
Bar-Hillel M, Peer E, & Acquisti A (2014). “Heads or tails?”–a reachability bias in binary choice. Journal of experimental psychology. Learning, memory, and cognition, 40 (6), 1656-63 PMID: 24773285