Flynn Effect

The Flynn Effect is the increase of intelligence test scores over the 20th century. The IQ measure is measured around 100 and their standard deviation on either sides. Over the years, the mean is adjusted based on the sample population and it is observed that the mean shifts upwards a few basis points.

There are a few explanations as to why this is a trend.

Total schooling time has increased steadily over the years. This means that kids would have had more chances to practice their analytical and cognitive skills.

Tests similar to IQ tests are used in a lot of scenarios. The familiarity of such tests has grown.

There is a more stimulating environment while kids are growing up now vs. back in the day. More video games and television stimuli. There are studies that show better cognitive activity and hand-eye coordination among those who game more.

Nutrition, both in quantity and quality has improved over time. There is data that suggests that the brain is ever so slowly growing as well with the improved conditions.

Better health conditions. Developed nations in general are more equipped to handle infectious diseases. Vaccinations are part of everyone’s growing life.

Forgetting Curve

A forgetting curve is a representation of memory retention over a period of time. Based on some early studies conducted by Ebbinghaus, it was shown that the forgetting curved follows a logarithmic curve. Given that there was no attempt to retain it. But how do you retain a memory.

Memories in our brain become more consolidated when we try to recollect it. That is why being tested on new concepts help you remember them more. However, testing yourself right after you learned something doesn’t help. This is where spaced repetition comes into play. The more spaced out the repetitions are more you can retain with a reducing effort every subsequent try.

When we encounter a new experience and we recollect an already existing memory. There are two possibilities that can happen. If the new experience is in agreement with the existing memory our brain consolidates even more. If it is differing, our brain creates a new memory based on the original memory. A representation is shown in the below picture.


de Oliveira Alvares, Lucas, and Fabricio H. Do-Monte. “Understanding the dynamic and destiny of memories.” Neuroscience & Biobehavioral Reviews (2021).

Evolving Content