magazine issue 2 2012 / Issue 14

It’s your choice! – Or is it really?

• written by Anna Sagana, Melanie Sauerland & Harald Merckelbach
• edited by Ashley Waggoner Denton

For most of us it is difficult to imagine that we could decide to buy a v-neck sweater and end up with round-neck collar without even noticing the difference. If this happened in a wide variety of situations, it would mean that we are often not fully aware of the decisions we make. According to researchers studying a phenomenon called choice blindness, this is precisely the case. Numerous studies have shown that we often fail to detect changes in our decisions (e.g., which of two jams we prefer) when that choice is secretly changed. In the present article, we examine when and why this phenomenon occurs, as well its implications for various real-world settings.

In the 1936 movie “Modern Times”, Charlie Chaplin struggles to live in the fast-paced modern society. As we move from the industrial age to the information age, societal demands on our mental capabilities are no less taxing. We are constantly required to process a wide range of information to make decisions. Sometimes, these decisions are trivial, such as what marmalade to buy. At other times, the stakes are higher, such as deciding which symptoms to report to the doctor. However, the fact that we are accustomed to processing large amounts of information does not mean that we are better at it (Chabris & Simons, 2009). Our sensory and cognitive systems have systematic ways of failing of which we are often (perhaps blissfully) unaware of. In the present article, we discuss two such fallacies of human cognition: change blindness and choice blindness. We will first provide an overview of these phenomena and then focus on the theoretical and practical implications of choice blindness in a variety of settings.

Enjoying a Walk and Being a Witness

Over the past decade, the change blindness phenomenon has been replicated many times (Davis, Loftus, Vanous, & Cucciare, 2008; Levin, Simons, Angelone, & Chabris, 2002). Especially noteworthy is an experiment by Davies and Hine (2007) who studied whether change blindness affects eyewitness identification. Specifically, participants were presented with a video enactment of a burglary. In the video, a man entered a house, walking through the different rooms and putting valuables into a knapsack. However, the identity of the burglar changed after the first half of the film while the initial burglar was out of sight. Out of the 80 participants, 49 (61%) did not notice the change of the burglar’s identity, suggesting that change blindness may have serious implications for criminal proceedings.

To most of us, it seems bizarre that people could miss such obvious changes while they are paying active attention. However, to catch those changes, attention must be targeted to the changing feature. We either need to expect the change to happen or our attention needs to be guided towards the changing feature (Simons & Rensink, 2005; Williams & Simons, 2000). In the study described above, participants were likely not expecting the change to happen, and so their attention may have been focused on the valuables the burglar was collecting rather than the burglar. This also explains, for example, why, while watching Ocean’s Eleven, you might not notice Brad Pitt’s cocktail glass filled with shrimps changing into a plate after an angle change, and then back into a glass again, while he is talking to Matt Damon in the Botanical Gardens. Similar changes occur in the Godfather, where the front windshield breaks when Sonny gets shot but is intact again only seconds later, or in Titanic where the deck anchor changes in the famous scene of Leonardo DiCaprio and Kate Winslet at the stern (retrieved fromhttp://www.moviemistakes.com).