Animal Research in Psych (HL)

A significant amount of research in Psychology has been carried out on animals.  You may have heard of Pavlov's dog, who became conditioned to salivate at the ring of a bell, or elaborate experiments involving rats who must navigate a maze to receive an award.  Animal experimentation raises two big questions - how useful are these studies for understanding human behavior, and even if so, is it ethical to inflict harm on animals?
TOK Link

In the short history of modern Psychology, there has been lots of disagreement over how best to study human behavior.  Recall some of the many different methodologies for studying behavior - lab experiments, correlational studies, case studies, brain imaging studies, and twin studies - to name just a few!  Ironically, some scientists have felt that the best way to investigate human behavior is to turn, instead, to animals.

So far this unit, we have looked at two examples of laboratory experiments carried out on animals - Rosenzweig & Bennet's study on neuroplasticity in rats, and Albert's study on how testosterone affects alpha male rat behavior.

Click on the links above to review these studies, and then consider the following:

1) Why do you think the researchers chose to use rats in their experiments, rather than humans? 

2) Do you think it was ethically justifiable to use rats in these experiments?

3) Do you think these experiments are relevant for understanding humans?  Why or why not? How robust is the knowledge developed through such animal research?
Why use animals in research?

Around 29 million animals are currently being used in experiments in Western countries.  Over 80% of these animals are rats and mice.  Why do so many experiments in Psychology involve animals?  Here are some of the  top reasons:

  • Ease of conducting research.  Lab rats are cheap and easy to store.  Human participants must be recruited, paid for their participation, and scheduled to come into the lab at a certain time.  Lab rats, on the other hand, can be experimented on at any time of the day or night, don't have to be recruited or paid, and will have to do whatever experimental procedure you want them to do, whether they like it or not.  For instance, in Rosenzweig and Bennet's study, some rats were placed in a cage, alone and with no stimulation, for 60 days.  Could you imagine how difficult (and expensive) it would be to pay a person to sit by themselves in a room for that length of time?

  • Less ethical concerns. Modern ethics commitees can be very strict about enforcing ethical guidelines in human research, and no study that causes physical or psychological harm to people will be allowed to proceed.  On the other hand, for better or worse, there are less strict ethical guidelines when it comes to animal research.  For instance, in Albert's study on testosterone, alpha rats had their testicles surgically removed - a procedure that would (obviously) never be allowed on humans.

  • Ability to study behavior over the lifespan​.  Since most animals live shorter lives than people, it is more feasible to study the effects of a variable over an animal's entire life span - or even into future generations.  For instance, one might study whether rats exposed to a stressful environment in rat childhood continue to suffer effects into old rat age, and even whether their rat children continue to suffer effects.

  • Ease of carefully controlling variables.  Although there are human research studies that span years (even decades), it is obviously impossible to control all the variables that a person might encounter over such a long time span.  On the other hand, psychologists can carefully control all of the variables for a lab rat (such as diet, type of cage, etc), establishing a clear causal link between the independent and depedent variables.  For instance, in Rosenzweig and Bennet's study, carefully controlling the environment that the rats were placed in demonstrated a clear causal relationship between a stimulating environment and neuroplasticity

  • Genetic similarity between rats and humans.  Rats and humans each have approximately 30,000 genes, but only about 300 are different between them.  As surprising as this may seem, rats and humans share 99% of their genes in common!  In fact, humans and rats share many of the same brain structures.  For instance, both rats and humans possess a hippocampus, the part of the brain that plays a key role in memory, and both human and rat behavior is influenced by testosterone, as suggested by Albert's research.
Think Critically

Rats and humans may have 99% of their genes in common, but that 1% of genetic difference sure does matter!  Although animal studies may be useful starting points, we should always be cautious when trying to generalize the findings of animal research to human beings.  We simply can't be sure that results from a rat experiment will apply to humans.

Consider the following:  a great deal of animal research has shown that giving rewards for a behavior will encourage more of that behavior in the future.  For example, if a bird presses a lever and receives a food pellet, they'll keep pressing that lever again to get more food.  This sort of research has been applied to schools and businesses - if you give rewards to students or employees, the thinking goes, they'll be more likely to perform well.

But is this always true?  Motivation in people is far more complicated than in animals.  Take a look at the video below, and consider the following:

  • What are the things (besides money) that motivate people?

  • What are some differences between motivation in humans and animals?

In general, animal research alone shouldn't be used to draw any firm conclusions regarding human behavior.  The findings from an animal study should always be supported by further research involving people.

IB Psych Matters: Ethics

Is it ethical to inflict suffering and death on animals in the name of psychological research?  Opinions on the ethics of animal research vary greatly.  Some argue that causing the death of some animals is a small price to pay for advancing knowledge, while others feel that no animals should ever be used in research.

Some countries have begun passing laws aimed at limited the number of animals used in research.  For instance, in 2010 the EU passed a law based on the principle of "3 R's":

  • Replace the use of animals with alternate techniques whenever possible

  • Reduce the number of animals used in a research study

  • Refine the way experiments are carried out to reduce animal suffering and ensure that animals are kept in humane conditions

Choose a side:  Are you "for" or "against" the use of animals in research?  Use the following resources to research three arguments to support your position.  Also, become familiar with the arguments used by the other side in order to think of counter-arguments.

  • Video: See below

More animal research

To further your understanding of how animals can be used in research, make notes on the two studies below.  For each study, consider the following:

  • Why do you think animals were used in the research study, rather than people?

  • What are some advantages and disadvantages to using animals in this study?

  • To what extent are the findings of this study relevant for understanding human behavior?

  • Do you consider the use of animals in this study to be ethical?
Study #1 - Francis et al - This study investigates the role of epigenetics in rat behavior.  Baby rats that are licked often by their mothers (a sign of affection) grow up to be less stressed out as adult rats, and also lick their babies a lot when they become mothers.  But is this genetic, or epigenetic?  Read this article to find out!

Study #2 - Waran and Tod - This study investigates the effects of pheromones on the behavior of dogs.  Lactating bitches release pheromones three days after birth to comfort their offspring.  Can a synthetic imitation of this pheromone affect dog behavior?  Read this article for the answer!
Research: Francis et al

Aim:  Investigate how an interaction between genes and the environment influences how rats nurture their offspring 

Procedure:  Within 12 hours of being born, researchers switched baby rats born to "high licking" mothers with baby rats born to "low licking" mothers (licking is a sign that mother rats are caring and loving to their offspring)

Findings: The rats that were raised by "high licking" mothers grew up to be less stressed, and eventually became "high licking" mothers when they had children of their own, even if their biological mother was a "low licker".  Through an examination of genes related to maternal care, researchers found that rats raised by "high lickers" had lost the methyl groups around these genes, causing those genes to be "turned on".

Conclusion: Being raised in a nurturing, loving environment causes changes in genetic expression.  These epigenetic changes are then passed on to the next generation.


  • This was a carefully controlled lab experiment, showing a clear causal relationship between the independent variable (being raised by a high vs low licking mother) and dependent variables (stress in adulthood, and maternal behavior after having children)

  • Use of animals in this experiment had several advantages: switching babies with different mothers would be highly unethical if done to humans, and the shorter lifespan of rats made it easier to study behavior across generations

  • Since this experiment was done on rats, it cannot be said for certain that these epigenetic changes also occur in humans

Research: Waran & Tod

​Aim: Investigate the effects of DAP ("dog appeasing pheromone") on the behavior of dogs in an animal shelter

Procedure: DAP is a synthetic chemical that mimics the pheromones released by lactating bitches three days after birth.  DAP was released in the air to 37 dogs, while 17 dogs received no pheromones.  A graduate student (who wasn't aware of which group received DAP) then observed the dogs' behavior for one week.

Results: DAP dogs barked less frequently, and showed more interest in strangers who approached their cage.  Sound meters registered a peak decibel level of 80 db for the DAP dogs, compared with 100 db for the control dogs

Conclusion: Pheromones send chemical signals to dogs that make them less anxious and more relaxed


  • This was a well-controlled laboratory experiment, showing a clear causal relationship between the independent variable (DAP or none) and dependent variable (dog behavior)

  • The use of animals in this study was ethical, as no dogs were harmed.  Furthermore, this research may have benefits for these animals

  • This study suggests that DAP may be used to help calm down anxious or difficult to handle dogs.  However, since pheromones are specific to each species, it is unlikely that DAP would have effects on other animals or humans

  • I can discuss a number of reasons why animal research is useful

  • ​I can explain why the findings from animal research may not be generalizable to humans

  • I can evaluate arguments for and against the use of animals in research

  • I can summarize the Aim, Procedure, Findings, and Conclusion, and Evaluate the research study by Francis et al on epigenetics in rats

  • I can summarize the Aim, Procedure, Findings, and Conclusion, and Evaluate the research study by Waran and Tod on the effects of pheromones in dogs
Quiz Yourself!

1.  Why is it easier to study animal behavior across the lifespan?

(a) There are less strict ethical guidelines when it comes to animals

(b) Animals, unlike humans, are not required to give consent to being studied

(c) The use of animals is less expensive, since humans must be paid to participate

(d) Most animals live much shorter lives than humans

2.  How much of the rat and human genome is shared?

(a) 9%

(b) 90%

(c) 99%

(d) 99.9%

3.  What is the most important difference between motivation in humans and animals?

(a) Tasks in humans often involve cognitive skill, not just mechanical skill

(b) Humans are primarily motivated by money, while animals are motivated by food

(c) It is unethical to use punishment in humans, while it is acceptable in animals

(d) Intrinsic rewards are not effective when motivating humans

4.  Which of the following is NOT one of the "3 Rs" in the EU law on animal welfare?

(a) Refine

(b) Recycle

(c) Reduce

(d) Replace

5.  Why do rats raised by "high licking" mothers go on to become high lickers themselves?

(a) They learn that mothers are supposed to lick their babies

(b) Babies born to "high lickers" have genes that ensure they will also become high lickers

(c) Maternal care modifies expression of genes

(d) Epigenetics demonstrates how nurture is more important than nature


​1 - D, 2 - C, 3 - A, 4 - B, 5 - C