The Suggestible Brain summary

Australia is a vast and often unforgiving land. European colonizers struggled to map it, and many of their attempts to navigate the continent ended in death. But the Aboriginal peoples, indigenous to Australia, developed an intricate and ingenious navigation system rooted in their deep connection to the land: songlines.

Aboriginal songlines are oral storytelling and navigation systems that map the Australian landscape through songs, each detailing the journeys of ancestral beings who shaped the land. These paths, sung in sequences, contain vital information on landmarks, water sources, flora, fauna, and survival practices. For millennia, they have enabled Indigenous Australians to traverse vast territories while preserving and passing down cultural knowledge.

In a Stanford University study, participants were presented with two vanilla milkshakes. While they looked identical, one milkshake was labeled as containing 600 calories. The other milkshake was labeled as containing a mere 140 calories – participants were told it was a prototype of a new, healthy line of shakes that, thanks to state of the art food technology, were just as tasty as their more indulgent counterparts. The participants were instructed to drink each shake until they felt satiated. Most drank far less of the indulgent high calorie milkshake before they reported feeling full, but were able to manage far more of the low-cal alternative.

Do you see where this is going?

Professor Elizabeth Loftus, a leading expert on the effects of suggestion on memory, has a uniquely personal connection to her field. When she was fourteen years old, Elizabeth lost her mother in a tragic drowning accident. At first, she had little memory of the accident but, when an older relative reminded Elizabeth that she had been the one to find her mother’s body, she started to remember it more clearly, right up to the firemen on the scene who gave Elizabeth oxygen.

Years later, though, the relative called Elizabeth to apologize. They had been mistaken and Elizabeth had actually not found her mother’s body. Through her relatives suggestion, Elizabeth’s mind was implanted with, and went on to develop in great detail, what is known as a ‘false memory’

In the 1950s, psychologist Solomon Asch conducted a series of groundbreaking experiments, now famously known as the Asch studies. These found that individuals can often alter their beliefs, actions, and reasoning in order to conform to the expectations of a group. In one study, actors within a group of participants were instructed to describe a picture incorrectly. Remarkably, many real participants followed suit, describing the picture incorrectly as well. In fact, the Asch studies found that around 75% of participants conformed to a blatantly wrong answer, simply to avoid standing out or risking ridicule.

What does this show us? Suggestion and expectation can create impact not just individually, but across group settings. At its extreme, this phenomenon can manifest as mass suggestion, also known as mass psychogenic illness – a psychological occurrence where people in a group display similar symptoms or behaviors without a clear physical cause.