Analyzing the answers that the volunteers provided to questions about their favorite music, food, hobbies, as well as about choices concerning friends and vacations, Quoidbach, Gilbert, and Wilson compared people at different stages of life and came to a couple of conclusions:

1. The older you get, the less you believe you have changed or will change. This finding isn’t surprising: for years, researchers have confirmed the common-sense idea that one’s personality and preferences become more stable with age. At 80, your grandfather will likely disparage whichever political party he opposes with more ferocity than he did at 65. As the Science research explains, even young people feel their current qualities are good qualities. They find it hard to imagine their beliefs and values could significantly change—even though most of us actually change our views often as time progresses.

2. In a similar vein, people have a tendency to recognize that their personalities and preferences have changed in the past but misunderstand that personalities and preferences often change in the future. As part of the research, the researchers compared how self-reported personality traits had changed among 3,808 adults recruited not by that French TV show but by the MacArthur Foundation. The participants had completed a personality survey (as part of a larger study called MIDUS, for Midlife Development in the United States) in the mid-’90s and then again in the mid ’00s. Among other things, MIDUS measures what are called the Big Five personality traits: conscientiousness, agreeableness, emotional stability (sometimes called neuroticism), openness to experience, and extraversion. (You can test your Big Five here.)