Species typically live in groups where they should involve in cooperation with other living creatures for feeding, breeding, and others. Non-human primates can use various signals and cues to achieve the tasks above. Számadó (2011, p. 4) indicates that the two can influence the receiver’s behavior, while signals are peculiar since they can increase the signaler’s fitness to this function. Anthropologists and biologists have agreed that non-human primates can offer either honest or deceptive signals, depending on a specific situation. The essay will demonstrate that animals would benefit more by providing one another with truthful information when food and sex are involved.
To begin with, one should explain why non-human primates engage in deceptive behaviors. On the one hand, Pfefferle et al. (2008, p. 571) stipulate that Barbary macaques can use their copulative calls to cheat and present false information regarding their fertile phases. This strategy results in the fact that females attract more males to influence mating outcomes. The sperm competition and paternity confusion hypothesis typically describe this process. According to Pfefferle et al. (2008, p. 576), this approach is beneficial for females because, in the Barbary macaque, paternity confusion can lead to the fact that multiple males will provide care to infants. Garcia and Ravignani (2020, p. 1) also indicate that dishonest vocalizations are used to create an exaggerated impression of signalers’ body size. On the other hand, cheating can generate some advantages in relation to feeding. For example, tufted capuchin monkeys can “use false alarm calls during feeding in a manner that functions to deceive competitors” (Kean et al., 2017, p. 37). These findings reveal that there is some robust reasoning behind primates’ cheating.
Even though the information above seems undeniable, it is reasonable to consider the opposite side. It refers to the fact that cheating can imply adverse consequences for non-human primates when it becomes discovered by other creatures. Thus, there exist numerous theories to describe the rationale behind following honest behaviors by these animals and what outcomes this strategy brings. That is why the following paragraphs will comment on these theories and explain why it is more beneficial for non-human primates to provide truthful information.
The first argument against being deceptive is that this approach wastes primates’ valuable resources. It mainly refers to those cases when sex is involved. For example, Zinner et al. (2004, p. 77) offer the reliable-indicator hypothesis showing that “sexual swellings are honest indicators of female quality because they are costly to produce.” Simultaneously, Vaglio et al. (2021, para. 2) demonstrate that the graded-signal hypothesis also focuses on this feature because female olive baboons should be honest to attract the best males. The rationale behind this claim is that strong-smelling vaginal secretions perform this function, meaning that primates’ odor depends on their physiological conditions that cannot be impacted for cheating (Vaglio et al., 2021, para. 9). Furthermore, Gouzoules and Gouzoules (2002, p. 842) admit that signals are typically accurate based on their cost. These findings reveal that being deceptive implies some noticeable disadvantages for non-human primates.
However, it is not reasonable to ignore the fact that honest behavior can also have drawbacks. For example, it refers to male ring-tailed lemurs’ “olfactory displays of anointing wafting tails to females” (Walker-Bolton and Parga, 2017, para. 1). On the one hand, this strategy attracts females, which is necessary to meet the reproduction goal. On the other hand, the behavior subjects these primates to higher levels of aggression from other ring-tailed lemurs. It allows for supposing that it is not a rule that honest behavior only offers benefits.
The second argument against deception refers to the situations when food is involved. It can occur that non-human primates fail to announce food discoveries not share the findings with others. Hauser (1992, p. 12137) demonstrates that such a failure can result in significant aggression against silent rhesus monkeys; these female discoverers also ate less food compared to those who announced their findings. Figure 1 below summarizes this information and offers a visual representation of why deception is not appropriate for non-human primates. Diagram A reveals an average amount of time of receiving aggression, Diagram B presents a number of aggressive acts, while Diagram C demonstrates an amount of food that was given to female discoverers (Hauser, 1992, p. 12138). Wright et al. (2021, para. 3) also indicate that dishonest signals can be punished by other creatures, and the punishment is severer for low-quality primates. Consequently, there are essential stimuli for non-human primates to avoid deception in their behavior.
Even though the information above demonstrates that deception leads to numerous disadvantages, it also brings another essential point that is worth considering. It refers to the fact that being honest does not protect rhesus monkeys from other primates’ aggressive behavior. Simultaneously, the case with male ring-tailed lemurs has demonstrated that honesty also subjects them to aggression because other males can consider their olfactory displays a threat. That is why it is necessary to follow a critical thinking approach to explain why honesty is more beneficial for multiple non-human primates.
At this point, one should draw attention to the fact that the two behavior models, honesty and deception, imply both benefits and disadvantages. Since this relationship exists, it is necessary to assess these consequences to compare their effects. Firstly, a non-human primate can face aggression and the necessity to deal with rivals irrespective of whether signals are honest or deceptive. However, sufficient evidence proves that the amount of punishment is essentially higher when it is revealed that a primate is a cheater. Secondly, the benefits of honest behavior are more significant because this strategy does not result in the fact that primates should waste costly resources of their bodies. It relates, for example, to specific swellings that are linked to physiological conditions, meaning that female primates should carefully use them. Higham (2014, p. 10) proves the thought above since the researcher indicates that primates engage in honest behavior when the cost of cheating outweighs its potential benefits. Consequently, since it occurs that deception can bring more harm than advantages, some primates tend to refrain from this behavior and typically follow honesty in situations where food and sex are involved.
In conclusion, the essay has demonstrated that non-human primates can behave honestly or deceptively in the same situations. They can send vocal and olfactory signals to reveal, hide, or present wrong information. Each of these strategies offers benefits and drawbacks, and multiple theories try to explain primates’ decisions. While the paternity confusion theory and desire to eat more food present the argument for deception, the reliable-indicator and graded-signal hypotheses oppose it. Credible evidence and critical thinking approaches have revealed that honesty is more beneficial for non-human primates when food or sex are involved because deception costs outweigh its potential advantages.
References
Garcia, M. and Ravignani, A. (2020) ‘Acoustic allometry and vocal learning in mammals’, Biology Letters, 16(2020081), pp. 1-7.
Gouzoules, H. and Gouzoules, S. (2002) ‘Primate communication: by nature honest, or by experience wise?’ International Journal of Primatology, 23(4), pp. 821-848.
Hauser, M. D. (1992) ‘Costs of deception: Cheaters are punished in rhesus monkeys (Macaca mulatta)’, Proceedings of the National Academy of Sciences, 89, pp. 12137-12139.
Higham, J. P. (2014) ‘How does honest costly signaling work?’ Behavioral Ecology, 25(1), pp. 8-11.
Kean, D. et al. (2017) ‘Feeling anxious? The mechanisms of vocal deception in tufted capuchin monkeys’, Animal Behavior, 130, pp. 37-46.
Pfefferle, D. et al. (2008) ‘Female Barbary macaque (Macaca sylvanus) copulation calls do not reveal the fertile phase but influence mating outcome’, Proceedings of the Royal Society B, 275, pp. 571-578.
Számadó, S. (2011) ‘The cost of honesty and the fallacy of the handicap principle’, Animal Behavior, 81, pp. 3-10.
Vaglio, S. et al. (2021) ‘Olfactory signals and fertility in olive baboons’, Scientific Reports, 11(8506). Web.
Walker-Bolton, A. D. and Parga, J. A. (2017) ‘’Stink flirting’ in ring-tailed lemurs (Lemur catta): male olfactory displays to females as honest, costly signals’, American Journal of Primatology, 79(12). Web.
Wright, E. et al. (2021) ‘Chest beats as an honest signal of body size in male mountain gorillas (Gorilla beringei beringei)’, Scientific Reports, 11(6879). Web.
Zinner, D. P. et al. (2004) ‘Sexual selection and exaggerated sexual swellings of female primates’, in Kappeler, P. M. and van Schaik, C. P. (Eds.) Sexual selection in primates: new and comparative perspectives. Cambridge: Cambridge University Press, pp. 71-89.