Our view of the world tends to be relative, instead of absolute, meaning that our behaviors depend on whether current conditions are better or worse than before.

An absolute view of the world may render us inadaptable to the changes we experience in our every day lives.

These comparisons between good and bad, past and present create either a positive or negative contrast effect. Contrast effects result from adaptation, or the lack thereof, to uncertainty and instability in one's changing environment.

A new study suggests that comparisons of current and past conditions allow for greater adaptability and survival. This opposes the standard theory, stating that ideal responses to current situations are unaffected by past occurrences. The ability to learn from the past and adjust to behaviors that promote survival in all conditions is favorable since environmental fluctuations are unpredictable, no matter what one's past experiences are.

The researchers used mathematical models to compare changes in behavior. Often, if an animal lives in poor conditions and is presented with favorable conditions, it will recall the unfavorable conditions it endured and exert the same energy to survive in the favorable conditions as it did in the past, though it is not necessary - this is a positive contrast effect. Past conditions then are the only way the animal can judge whether conditions are likely to change in the future, and much of the time, they wil not expect a drastic change when normally faced with difficulty.

A positive contrast effect means that an animal exerts the same, if not more, effort to survive when presented with a different environment. In the study, this was usually seen when an animal was taken from an unfavorable environment and put into an advantageous environment.

A negative contrast effect means that the animal does not exert more effort to survive when put into a different environment. This phenomenon was seen among animals who were taken from favorable conditions and put into unfavorable ones. They did not have the same urgency for survival that the positive contrast effect animals did, even though they should have.

Co-author Dr. Tim Fawcett, Ph.D., noted that the environment is full of rapid changes. "Rapid changes favor individuals that are responsive and able to adjust their behavior in light of past experience," he noted. Fawcett suggested that animals with the positive contrast effect are better off than those experiencing the negative contrast effect because they actively work toward survival, while the others wait around for conditions to improve.

Both contrast effect groups normalize to a baseline amount of effort, indicating their adaptability, but the difference in immediate responses between the two groups is of interest. Basing decisions on past experiences can be ideal because the current conditions are unpredictable, while previous outcomes can now be referenced and learned from. Adaptability of both groups is of interest. "The negative contrast effect gradually weakens as the poor conditions continue...the conditions after the shift continue to change the animal's belief about the true state of the world," Fawcett said.

Animals accustomed to poor conditions may be more compliant to change, simply because their urgency for survival does not change based on their environment. Survival skills in animals can be compared with decision making skills in humans because each are driven by the need for a similar outcome - endurance.

What does this mean in terms of our decision making skills? Those with experiences to reference will likely be more cautious of past outcomes and make decisions accordingly. Decisions based on past experiences, according to this study, are the most informed ones and are usually the best path to take, as nothing can be predicted about current conditions, but much can be learned from the past.


Source: McNamara JM, Fawcett TW, Houston AI. An Adaptive Response to Uncertainty Generates Positive and Negative Contrast Effects. Science. 2013.