Behavior can be scientifically investigated

Stanford County Prison - thanks to

They're a bit like computer hackers - but instead of deciphering digital algorithms, behavioral researchers trace nature's rules of action. Why do animals and people behave this way and not differently in certain situations?

Scientific supervision: Prof. Dr. Boris Suchan

Published: 06/30/2016

Level: medium

  • Behavioral research examines the causes, backgrounds and rules of behavior.
  • Questions are, for example, what external reasons there are for behavior, what biological processes are based or what benefit a living being has from them.
  • Behavioral research uses an extensive arsenal of methods. Researchers observe animals and people in the wild, encourage them to solve tasks in the laboratory or model their behavior on the computer.
  • The results of behavioral research can improve species protection and the welfare of farm animals and reveal new points of attack for medical interventions. The evolution of behavior is also an aspect of research.
  • Behavioral research can be easily combined with neuroscientific measurement and intervention methods.

What at first sounds like a simple question turns out to be complex on closer inspection. Nikolaas Tinbergen, one of the founding fathers of modern behavioral biology, already emphasized this when he committed his discipline to answering four “basic questions of biological research”: What causes the behavior directly; what benefit arises from this for the individual; how has the behavior developed in the course of the life of the individual; and how did it come about in the course of tribal history?

For the search for answers, behavioral biology offers an extensive arsenal of methods. In field studies, scientists follow their study objects over hill and dale and observe them - if necessary with aids such as microphones, hidden cameras or even detective work: For example, they pick clues about eating habits from animal droppings and decipher them using thousands of cutting patterns in leaves, such as New Caledonian crows tools to build.

In order to test hypotheses about triggers, origins, meaning and regularity of behavior, however, controlled experiments are required. These usually follow an experimental setup that is basically simple. They expose test animals or human test persons to various stimuli in order to test their behavior-inducing effects. Or they give the test subjects a choice in order to measure their preferences. Or they encourage them - often with the prospect of reward or punishment - to solve a task in which certain aspects of the cognitive or psychosocial repertoire have to be developed.

There are hardly any limits to the imagination of the experimental designer when it comes to designing the actual experimental setup. For example, researchers make mock-ups for fish to investigate courtship preferences, build elephant-sized mirrors to test whether the proboscis recognize their own likeness (video) or invent puzzle tasks in which the test objects have to use objects in a certain way to get the desired result. For example, it can be examined how far an animal or child thinks into the future, how well it can understand or even build tools, or what it knows about what others feel or think.

If certain rules of behavior have proven to be plausible in observational studies or in experiments and they can also be replicated, a mathematical model can give the hypothesis the final touch. Virtual individuals are equipped with the characteristics and strategies to be examined and let loose on one another in the computer biotope. Since environmental conditions and behavioral patterns can be precisely controlled in the program and the evolution here runs in fast motion, such models open up a further perspective for behavioral research that is difficult to achieve in the confusing nature.

Originally driven by the curiosity of classic naturalists about the ubiquitous cabinet of animal curiosities, behavioral research has long since achieved practical relevance. The primate researchers Jane Goodall and Dian Fossey, for example, opened up a glimpse into the worlds of action, thought and experience of chimpanzees and gorillas in the wild in the 1960s and 70s and thus broke a lance for the protection of species. In order to make the life of farm animals more bearable, researchers found in experiments that a dust bath gives comfort to factory-farmed chickens, mink in fur farms are keen on snacks and paddling pools and piglet stress can be alleviated by taking breaks from play.

Many studies attempt to decipher the biological basis of behavior - often with the aim of better understanding human behavior or of achieving medically relevant results. Eric Kandel (here in our interview) received the Nobel Prize in 2000 for his research into how the interaction of certain neurons and molecules allows sea snails to learn and form memories. Today, learning and memory tests are part of the standard repertoire of many studies. Usually it is mice or rats that are sent through mazes on land or water or are reminded of unpleasant encounters with hot plates - for example to check whether certain brain regions, cell types or pharmacological substances influence cognitive performance.

Other researchers are more concerned with the evolutionary derivation of behavior. They examine complex cognition in animals and humans, for example, with no less complex puzzle tasks. In a particularly impressive example in 2014, the crow "007" cracked an eight-level tool puzzle in which the bird first had to peel three stones from cages with a short stick and then throw them onto a seesaw to get a second, longer stick. which finally brought him within reach of a delicacy (video).

In behavioral studies with people, interactive games are often used, for example to examine willingness to cooperate, thinking strategies or empathy. A particular challenge in such psychological experiments is not to reveal too much to the participants about the researchers' interest in knowledge, so that the test persons do not adapt their behavior to them knowing the study goals. The Stanford prison experiment shows how quickly participants in psychological studies can get absorbed in the experimental situation. The test subjects felt so intensely into their roles as prison inmates and prison guards that within a short period of time there was an escalation of violence and the experiment had to be discontinued.

Charles Darwin (1809-1882) was a pioneer in behavioral research. The naturalist devoted countless hours at home and while traveling to observing the behavior of animals as diverse as pigeons, turtles and dogs. The results flowed significantly into the development of his theory of evolution. Nikolaas Tinbergen and "goose father" Konrad Lorenz followed in the first half of the 20th century. They developed the precise observation of animals in their natural environment into the discipline of comparative behavioral research (ethology). In the meantime, contemporaries Edward Lee Thorndike, Burrhus Frederic Skinner and Iwan Petrowitsch Pawlow, who examined how animals learn in the laboratory, were promoting a contrasting program that relied primarily on experiments. They invented the first puzzle cages to study how reward or punishment influenced animal learning and trained dogs to recognize bells as a food signal. Many experimental set-ups are still based on their findings on the conditioning of behavior.

With its diverse methodology, behavioral research enables complex patterns and rules of action to be deciphered. Behaviors are the end point of many brain activity. Understanding them and, if necessary, being able to influence them is therefore an important goal of brain research, often with medical relevance. Well-planned behavioral studies can make a decisive contribution, for example when it comes to questions about the causes of neurological and psychological diseases or the effectiveness of medical interventions.

However, the complexity and unpredictability of many behaviors and the personality of the test participants also lead to many sources of error, especially in the case of intelligent test animals and human test persons. In the training phases that are often necessary before experiments, the relationship between the test animal or test subject and the trainer can distort the subsequent results, for example if the test subjects develop a feeling for the expectations of the testers - or if they overinterpret the actions of their test participants. Evaluations prove at least: one third of the results of psychological studies could not be replicated in a sample by other research teams. Pure behavioral observations, on the other hand, run the risk of remaining mere anecdotes due to the lack of control over the diverse environmental conditions.

A rigorous study design provides a remedy - for example, commissioning different people for training, testing and evaluation phases. The careful combination of different experiments and, ideally, observational and modeling studies can also minimize sources of error.

Possible combinations

Behavioral research can also be combined well with many other neurobiological methods. Both mice and humans can, for example, be equipped with electrodes during a behavioral experiment that measure brain waves via EEG or even influence them through transcranial magnetic stimulation. In the case of human test persons in particular, the combination with imaging methods is also ideal to find out which brain regions are active in certain behaviors. In the case of invasive methods, which are usually only used on test animals, an animal is first subjected to an intervention, such as an operative change in the brain or a genetic or pharmacological manipulation of specific functions. Then the effects are examined in the behavioral experiment.

Behavioral research is developing primarily with a view to the increasingly precise possibilities of examining and manipulating the function of individual cells and molecules in the brain. New genetic methods, with the help of which specific neurons or circuits in the brain can be switched on and off with lightning-fast light (optogenetics) or by adding certain chemical substances, make it possible to ask and answer much more precise questions about the development of behavior. The classic experimental set-ups are likely to remain in place. In the test laboratories of the future, rats and mice will also walk through mazes.

for further reading:

  • Tinbergen N: On aims and methods of ethology. Journal of Animal Psychology. 1963; 20: 410 - 433 (for the full text).
  • Behavioral biology. Peter Kappeler, Springer, Berlin / Heidelberg (2012).
  • The Psychological Experiment: An Introduction. Oswald Huber, Göttingen (8th edition, 2013)