Most research involving non-human animals takes place in laboratories. However, that is by no means the complete picture. Cuthill (1991) considered over 900 research papers, and found that 46% of them were field studies carried out in the wild. About one third of the field studies were field experiments, meaning that they involved some kind of experimental manipulation. The four most common types of manipulation used in these studies were as follows:
Dummies: these were mainly stuffed dummy predators; in order to be effective, they need to be realistic, and this means that they cause much distress to animals who encounter them.
Non-trivial handling: tagging or marking of animals so they can be identified subsequently is an example of this; as mentioned already, this can be a stressful procedure.
Playback of recorded signals: these recorded signals are generally realistic; if they are alarm calls, then this can lead to high levels of distress.
Food addition: when the experimenter artificially introduces food into an area, it can cause territorial disputes and fights; it can also lead to undesirable changes in the availability of the animals’ normal sources of food supply. Thus food addition can have serious consequences for the animals affected.
Activity: The use of non-human animals in psychological research
Animals in Research
We will shortly be considering the kinds of ethical guidelines that have been developed to try to ensure that all animal experimentation is ethically sound. The single most important safeguard is that the experimenter should everything possible to minimise the level of discomfort or suffering experienced by the non-human animals involved in the research. This safeguard needs to be considered in the context of the importance of the research. It is far more acceptable to cause some suffering to non-human animals if the goal of the research is to develop more effective drugs for the treatment of schizophrenia than if the goal is a trivial one (e.g., to enrich a company making cosmetics). In other words, it is very important to carry out a cost–benefit analysis on any proposed research to ensure that the benefits will outweigh (and ideally greatly outweigh) the costs involved.
These safeguards are relevant to what is known as Bateson’s decision cube (discussed more fully later). According to Bateson (1986), when considering whether any given experiment on animals is justified, we need to take account of its quality, the suffering that will be involved, and the likelihood of benefit (see the Ethical Principles section below).
Animals and medicines
Animal research has been very useful in the medical field, and has led to the saving of millions of human lives. For example, Alexander Fleming discovered penicillin in 1928. However, it was only in 1940 that research on mice showed that penicillin was a very effective antibiotic. Another example concerns kidney dialysis, which is required by about 200,000 people every year in the United States if they are to stay alive. The drug heparin is essential for dialysis, and it has to be extracted from animal tissues, and then tested for safety on anaesthetised animals.
Animals and psychological research
The benefits of animal research are less clear in psychology than in medicine. However, there are several reasons why psychologists use non-human animals in so many of their experiments.
Research involving physical harm
It is possible (although there are major ethical considerations) to carry out surgical procedures on non-human animals that simply wouldn’t be permissible with humans. Gray (1985) discussed animal research designed to identify those parts of the brain associated with anxiety. This animal research stemmed from work on humans, in which it was found that anti-anxiety drugs such as the benzodiazepines and alcohol had 19 separate effects. These findings were compared against those of animal studies in which the effects of septo-hippocampal lesions or cuts were observed. The effects of these lesions were very similar to those of anti-anxiety drugs in humans in 18 out of 19 cases. It is probable that the septo-hippocampal system is involved in anxiety, and so lesions or cuts in it produce the same non-anxious behaviour as anti-anxiety.
It is possible to expose non-human animals to prolonged periods of social or other forms of deprivation. For example, studies have been carried out on monkeys that weren’t allowed to interact with other monkeys for the first few months of life. When monkeys that had been brought up in isolation were brought together, they reacted very aggressively (Harlow & Mears, 1979). Early isolation also produced a virtual absence of a sex life in adulthood. These findings indicate the potentially severe effects of social isolation. In another of Harlow’s studies (Harlow & Harlow, 1962), young monkeys were placed with surrogate wire mothers. These wire mothers responded to the young monkeys in various ways (e.g., protruding metal spikes, strong blasts of air). The procedures themselves pose ethical issues, but of more concern are the long-term adverse effects on the monkeys. In the research by Harlow and Harlow, for example, the young monkeys as adults had problems in reproduction and in providing adequate parenting for their offspring.
The members of many species develop and reproduce over much shorter time periods than do members of the human species. As a result, it is much more feasible to carry out studies focusing on the effects of either heredity or early experience on behaviour in such species. For example, in one study a breeding programme was used to produce rats either reactive or non-reactive to loud noise and bright lights (Eysenck & Broadhurst, 1964). The reactive rats were much more anxious than the non-reactive ones in a wide range of situations. These findings suggest that individual differences in anxiety depend in part on genetic factors.
Simple and complex behaviours
It is generally accepted that the human species is more complex than other species. It may thus be easier to understand the behaviour of other species than that of humans. This makes animal research very useful, provided we assume that other species are broadly similar to our own. This line of argument was used by the behaviourists to justify the fact that rats (rather than humans) were used in most of their experiments.
Beneficial non-human animal research
Much animal research is acceptable to nearly everyone because it is clear that the ends justify the means. Malim, Birch, and Wadeley (1992) discussed examples of such animal research. One programme of research was designed to provide us with a better understanding of the behaviour of animals that damage crops. This research led to the development of more effective scarecrows, so that more unpleasant methods of preventing crop damage (e.g., poison) were no longer needed. In this case, animal research actually served to produce a large reduction in animal suffering.
Another example of animal research that was almost entirely beneficial in its effects was reported by Simmons (1981). Pigeons were carefully trained by means of operant conditioning to detect life rafts floating on the sea. Pigeons have excellent vision, and so their detection performance was much better than that of helicopter crews: 85% detection compared with only 50%. In this case, animal research has enabled many human lives to be saved.
Psychological examinations of animals can produce benefits for the animals themselves. Examples include wildlife management programmes, efforts to preserve endangered species, and conservation programmes. Of course, these programmes (while of benefit to the animals involved) are primarily used because they help to achieve goals of importance to the humans who initiate them.
How many animals are used in psychological research? Thomas and Blackman (1991) answered that question for psychology departments in the United Kingdom in 1977 and 1989. The figure for the earlier year was 8694 animals, whereas it was only 3708 animals in 1989. This dramatic reduction over a 12-year period has almost certainly continued since 1989. Several species were used in psychological research, but about 95% of the total was accounted for by just three species: the mouse, the rat, and the pigeon.
Between 1977 and 1989 the numbers of animals used in experiments in the UK reduced considerably:
The total figures for animal research of all kinds are declining year by year, but are still very high. According to Mukerjee (1997), about 1.5 million primates, dogs, cats, guinea pigs, rabbits, hamsters, and other similar species are used in laboratories in the United States each year. In addition, however, about 17 million rats, mice, and birds are used in American research every year.
The American Psychological Association released figures in 2005 indicating the scope and nature of psychological research on non-human species. About 7–8% of psychological research involves animals, and about 90% of the animals used in such research are rodents and birds (e.g., rats, mice, pigeons). Monkeys and other primates are used in only 5% of experiments in psychology, and cats and dogs are used only rarely.