Preference for the known and familiar increases with ageing, and this preference is better explained by changes in grey matter in a certain brain area rather than by age, a study published in Nature Communications shows.
When people make decisions that involve risk, or put another way, uncertain outcomes, an area of the brain called the right posterior parietal cortex is active. The amount of grey matter in this area has been show to correlate with risk preference in young adults. As people age, they tend to make fewer risky decisions, but whether this is due to the wisdom that comes with age or brain structure was unknown.
Ifat Levy and colleagues asked 52 adults, spanning the ages of 18-88 years, to make a choice between a certain option (gain of $5) or an uncertain option (possible gain ranging from $5-$120 with random probabilities). As expected, they found that the certain option is preferred by older participants compared to younger participants, and that this preference for the certain option increased with age. When they put these data into a model to determine which variable best predicted this change in preference, they found that it was primarily driven by the amount of grey matter in the right posterior parietal cortex brain region, rather than by age. These results suggest that the changes in the brain that occur in healthy ageing may be responsible for more of our decision-making patterns and preferences than previously thought.