The theory is that all human actions can be expressed in terms of signals, markers, tokens and handles (SMTH). If a counterexample were found of something which cannot be fully described using SMTH, the theory would have to be abandoned. Yet no counterexample has emerged.

If human actions can be described by this means, then surely animal actions can be included too. Putting it a little more formally, if the model applies to human behaviour, then it must incorporate animal behaviour. Animals are simpler after all.

Animals are often used for experimentation and simulation of human physiology and behaviour, but here we do the opposite. We step backwards, as it were. The animal behavioural spectrum is limited in scope. Certainly, animals are more predictable.

An interesting issue is whether there is any human trait which does not exist among animals. It’s an intriguing theme. For example, it might be proposed that pair-bonding is unique to humans. However several bird species, prairie voles and some monkeys are monogamous. ‘Communicating over long distances, longer than line of sight.’ Whales do this. ‘Jealousy’ – dogs can exhibit jealousy and, according to reports, can even be self-conscious. In one instance, a dog was embarrassed to appear in public after a haircut. I was once a spectator as a duck showed off its flying abilities to me. Religious notions aside, it seems that the differences between humans and animals are quantitative, rather than qualitative.

Notwithstanding, this exploration will highlight some differences between humans and animals.

Signals

Signal and action are practically synonymous. One cannot make an action without giving a signal; the movement is the signal. Even a lack of movement is a signal. It could signify that an animal is dead, sleeping, or poised to strike. Among humans, failing to acknowledge someone is a signal.

A notable contrast is that human signals are ambiguous, while animal signals are not. Robert Trivers in his book Deceit and Self-Deception relates an occasion when he issued a false signal to a monkey. The monkey became so enraged that he became concerned for the safety of the child he had with him at the time. This encounter illustrates how the integrity of signals is maintained in the animal world.

Categorising human signals into the following four types I believe to be a significant achievement. The categories shall be detailed in turn, as applied to animal signals. Note though that I am not a zoologist, and there may well be exceptions to these generalisations that I am unaware of.

Honest signals

Animal signals are overwhelmingly honest. An animal’s movements and its displays accurately reflect its mood and intentions. A predator may lie in wait, but it will not engage in a conscious charade to capture its prey.

Of course deception does occur, but largely through form or colouring. These are structural or inherent mechanisms which, according to the overarching theory, have evolved mechanically by trial and error over millennia.

Erroneous signals

Erroneous signals in humans are problematic at the best of times; this is likely the most contentious category of signals, because their categorisation involves morality and often implicit social rules. Erroneous signals are valid (‘soundly based’) since they faithfully express an emotion or instinct. However, even if valid, the signal should be inhibited due to circumstances or social convention. A typical human erroneous signal would be a female signalling a male when she is not available. Another instance would be a diplomat failing to hide his personal dislike of another country’s representative.

An erroneous signal among animals might take place in a group of primates such as gorillas. There a single male is dominant, and his instinct is to drive out young, potentially rival males as soon as they reach a certain age. They must then go off and fend for themselves. A young male, approaching the age at which he would be expelled, expresses disdain or an implied threat to the dominant male. Then the pup is soundly thrashed and driven out rather sooner than had he not demonstrated impertinence.

Among lower animals erroneous signals seem to be rare, as they can easily lead to injury or death during the innumerable contests which take place. In social, equivalently, pack animals, such signals might lead to the animal being expelled from the group.

False signals

False signals are deliberately invalid. A typical human false signal is leaving a light on when no-one is at home. A bird may feign a broken wing to lure a predator away from its nest, but the vast majority of false signals in nature are structural – such as misleading colouring, as when an insect mimics a wasp, or a venus fly trap appears as a succulent plant.

Dysfunctional signals

Like erroneous signals, dysfunctional signals are maladaptive, and would probably attract a similar reaction from other animals. Dysfunctional signals are rare in wild animals because they are not so subject to high order dysfunction as a result of psychological stress. They are often evident in zoos however. The animal may repeatedly rock from side to side due to boredom and frustration at its forced captivity. Gorillas are reportedly quite intelligent, so it is no wonder that some go mad. A collection of such behaviour, termed “zoochosis,” is at www.bornfree.org.uk/campaigns/zoo-check/captive-wildlife-issues/abnormal-behaviours.

Markers

The original marker must surely have been scent. Such a cue is unambiguous. An animal does not mask or disguise its smell, which is inherent and often permeates a thick and waxy coat of fur.

A prey species may sniff the air to check for the presence of predators. A predator will often converge on its prey from downwind, but it will not bathe to lessen its scent. Animals often distribute their scent over a wide area and many have organs dedicated to this purpose.

Smell is particulate. That is, it involves particles of the substance. A good tracking dog, such as a bloodhound, can detect scent from a single molecule, an astonishing feat. Individual animals, not just species, can be identified by their scent. Urine and faeces have particular aromas and these are evidently delicious to the dog.

Animals likely navigate using an internal ‘scent map.’ A territorial landscape is stored and updated according to the location of food sources, enemy species and rivals. Animals unambiguously mark their territory by leaving scent.

Tokens

A promising animal model for tokens exists in the mating gifts found in the insect world. Males of some insect species present the female with a gift of food as a preliminary to mating, even an empty parcel to keep her occupied during copulation. Thus the male scorpionfly gives a ‘nuptial gift’ to his mate. The bower bird builds a structure filled with bright objects to attract a female, or a cock bird might display a piece of twig in his beak to denote his willingness to assist in building a nest. Each of these things represent something else. A male making a flattering or amusing comment to a female on approach is directly comparable to the nuptial gift of an insect.

Handles

If calling someone’s name is the basic handle, there is difficulty identifying a non-human archetype or original case of the mechanism. While dogs can respond to their name, there is no indication that social animals (such as horses) assign names to other members of their group. Individual animals are certainly identified, because a large amount of effort is often devoted to maintaining or increasing the animal’s position in the group hierarchy. Perhaps their ‘thought names’ take the form of ‘He is number three in the hierarchy, I am number four’ or ‘Smells like tree bark.’ Maybe the animal’s distinctive smell is its name – its smell is directly equivalent to its name. Whatever form these private names take, animals lack the ability to call them out.

Possibly the primordial (i.e. most basic or original) handle is that the female in oestrus presents to the male. Then, oestrus and being of the same species are the handle states. This primordial handle would be comparable to the “conjugal rights” a husband enjoyed until recently.

So, to conclude, signals, markers and tokens have clear analogues in the animal kingdom. The chief difficulty seems to lie with handles. A command to a trained dog is a handle, but this is an interaction between a human and a domesticated animal. In the wild, a signal from a dominant pack member for a subordinate to retreat is a likely candidate for an animal handle. It would be a handle in the form of a signal, and comparable to an officer issuing a command to a subordinate soldier, which is a formal handle in the human realm.