Five years ago, I decided to switch my major to Psychology—mainly to understand myself and others better, and hopefully tweak my behavior accordingly in different situations.

However, the deeper I got into the academic side of things, the more I realized it’s not that simple. Turns out, it’s illogical to use research findings to predict how an individual should behave in every scenario.
This concept is called the ecological fallacy
Ecological fallacy: using group-level data to make conclusions about individuals.
Here’s an example:
Company data shows that younger employees take fewer sick days than older employees. At first glance, it might seem like a random younger employee will take fewer sick days than an older one. But let’s break it down in this scenario:
Younger Group:
A: 2 sick days
B: 20 sick days
Average Sick Days:
Younger = (2 + 20)/2 = 11
Older Group:
C: 15 sick days
D: 16 sick days
Average Sick Days:
Older = (15 + 16)/2 = 15.5
While the younger group averages fewer sick days, person C (older) took fewer sick days than person B (younger). This proves a point: Group-level data doesn’t always reflect individual behaviors.
Conclusion
In statistics, techniques like multilevel modeling help us navigate these nuances, analyzing data at different scales. But when it comes to evaluating people—whether colleagues, employees, or friends—remember: they might just be that person C in the example.
Observe, avoid assumptions, and approach individuals as, well, individuals. Group data is useful for group decisions, but when you’re dealing with people, take time to understand them truly.
