Summary of:
Nairne, J. S., Thompson, S.R., & Pandeirada J. N. S. (2007). Adaptive Memory: Survival processing enhances retention. Journal of Experimental Psychology, 33, 263-273.
Summary by Malia Prietto, Joel Schreiber & Seth Matsumura
For Dr. Mills’ Psych 452 Class, Fall 2008
The evolution of all species evolved for a specific purpose in mind. They evolved in order to solve some problem that was presented to a species. It is widely accepted that memory is adaptive based on the environment and adversity. As problems arise, a species must figure out a way to fix them. Memory systems have evolved in order to function as a survival mechanism. They can allow us to remember where vital resources are, help us to remember who our trustworthy allies are, and in a grander scheme it can assist us in survival.
“Kareev (2000) has argued that fundamental capacity limits in immediate or working memory—the ubiquitous seven (plus or minus two)—maximize our ability to detect causality by forcing us to focus on small samples of information.” (Nairne et. al., 2007, pp 263). People can only hold so much information in their short term memory, so how does one select the most important information to hold here? Evolutionary psychologists place a great deal of importance on ancestral environments, suggesting that the adaptations that they had to acquire in order to survive were passed down to the present generation. It is suspected that our memory systems have evolved and adapted to help us to remember certain types of information better than others, in the case of this study, survival information.
The aim of this study was to see whether the adaptation of memory to survive still persists or if it is there to begin with. When placed in a survival situation, will your memory serve you better than when not in a dire situation? If so, then what is the mechanism causing this to occur? In four separate experiments this idea is tested. In the first test, participants were asked to make judgments about the relevance of words to a survival scenario. After judging the words and a short distraction period, they were given a surprise retention test of the words shown to them. They were either placed in a category where they were to imagine that they were stranded in a foreign land without basic survival materials. Other control groups were also used. Word recall was tested to see which scenario had the best outcome.
The same basic ideas were tested in the other three experiments, changing only a few things, such as making the test groups a within subjects group or a between subjects group, testing recognition memory instead of recall memory, and testing survival situation recall against self-reference recall. In all four cases, recall or retention in the survival scenario was significantly higher than the recall of the other control groups. This suggests that there is something innate in humans that cause them to retain memory better when they are faced with a more dire situation as opposed to a situation that is not life threatening.
It cannot be confirmed that humans have this ability due to the fact that ancestors to humans have developed an evolutionary adaptation to cope with this problem of survival that was passed down through generations. Nairne et. al. speculated about some other proximate mechanisms that could cause this outcome to occur. The idea of a general memory module was proposed as a specialized mechanism for recall of survival scenarios, but this was thrown out because a survival module is too general. “Nature, or at least the process of natural selection, would not develop or “design” an adaptation for survival per se; instead, specific modules or mechanisms are likely to develop for processing particular foods, predators, and the like,” (Nairne et. al., 2007, pp 270).
Another proximate cause proposed was that modern day inventions, such as the TV show could cause for a renewed perspective on life. The television shows Lost and Survivor were suggested as causes to peoples’ awareness of the need for survival tactics. Another post experiment was conducted testing subjects once again on recall of survival words with controls in place. The change was that people were questioned whether they watched either of these shows before the experiment began. Results still show that even if people had not watched the show before, that they still tend to remember words under survival scenarios significantly better.
These ideas are evidence that suggest that humans do in fact have some sort of innate ability to remember or recall scenes involving survival better than non-survival situations. The mechanisms which trigger this are still unknown, as is whether this is in fact an adaptation due to evolution from a time when recall in survival situations was very key. Though there is no proof, it allows for one to delve deeper into the mechanisms behind evolution and how this process even occurs.
Outline
I. Introduction
A. Memory is adaptive; varies by environment and adversity.
B. Suggested that ancestral environments have adapted humans to possess mechanisms to enhance survival.
- We tend to remember certain information better than others (survival info).
II. Memory as survival tactic
A. Humans remember aspects of survival situations better than other situations.
B. Humans recognize words used in survival tactics better.
C. Humans are more calibrated to remember survival scenarios better than self related topics.
- Survival more important than the self.
- Possibly adapted from ancestors.
III. Other proximate causes
A. Humans have adapted memory modules
- Too general
- Natural selection would not “design” a survival adaptation, but many small mechanisms combine to make one.
B. Survival advantage may not come from evolved mechanisms.
- May have come from reasons unrelated to survival
C. Modern society’s effect on human thinking, e.g. TV shows
- Tests show no significant difference from those who watch survival TV and those who don’t.
IV. Conclusion
A. Study shows evidence for possible reasons for survival bias in memory.
B. Could be due to adaptations evolved long ago.