The find is the latest result to come out of the Betula project at Stockholm University whose main purpose is to study how the memory develops and to find early signs of dementia.
“We have found out that the experience memory, also known as the episodic memory, improves for every generation,” according to Lars-Göran Nilsson, a professor of psychology at Stockholm University and the leader of the project.
The study has tested 4,200 randomly selected people between the ages of 25 and 80 over a 20 year period at five-year intervals. The duration of the research makes it unique, writes Svenska Dagbladet.
According to the researchers, education, nutrition and family size are the causal factors behind the development. Those with higher levels of education, fewer siblings and good nutrition and exercise habits have stronger episodic memory, the study has found.
“Put simply these results indicate that the pension age can be adjusted upwards as we retain better cognitive function as we age,” said Lars-Göran Nilsson.
Exactly how education affects memory is not specified by the numerical study, although Nilsson suggests the theory that it is to do with the training of abstract thought.
The reason for why those with fewer siblings have better episodic memories was easier for Nilsson to explain. The order of birth in a family is also of importance with those born first tending to have better episodic memories.
“It probably has to do with the fact that the first child receives 100 percent attention and then when the child gets siblings energy and time is shared accordingly,” Nilsson told Svenska Dagbladet.
The effect of nutrition on episodic memory is less easy to discern as genetic factors also play a significant role.
Nilsson is excited by the new questions that have emerged from the study and would like to see the results compared against similar research from developing countries which may not have the same levels of nutrition.
According to Nilsson, Chinese researchers have indicated a desire to participate in such a project.