This is the third and concluding post in the series where I attempt to discuss the importance of physiochemical effects of scent in fitness with regard to both health and sociality (see Scent signal transduction via chemical-neural pathways (remedial benefits) and Familiar scents as safe havens and golden standards).
In the previous post, I addressed the potential mechanisms through which olfactory experiences form memory and learning pathways aiding the evolution and development of social/territorial living and how social/territorial life (with its familiar and consistent olfactory presence) might lead to alterations in one’s metabolism.
While it is easy to understand why perhaps animals would grow attached to familiar scents of home and family (or other type of permanent social relations) to the point they would prefer these smells and even apply these smells to their own bodies (rolling, rubbing, allomarking etc.), it is less obvious why some species would also exhibit a similar intensity of devotion to scents of their competitors (neighbours, trespassers etc.).
Territoriality and sociality are sometimes connected and I believe that social scents are more important than exclusively territorial scents (for example, many otter species scent-mark and roll in scents of both familiar and less familiar/non-familiar individuals, it appears to me that social otter species (beyond mother-offspring bond) have more elaborate scent-marking and scent-‘celebrating’ rituals).
On one hand, it is inevitable that territorial species would have neighbours and trespassers.
When it comes to neighbours, it is also inevitable that some of the mechanisms present in the development of social attachments to affiliates would also apply to neighbours.
For example, if the residential pattern is more or less permanent (which it often is because that is the whole point of founding a territory), scents by neighbours would also be memorized, individualized, historicized and possibly adapted to.
Species that mark territorial boundaries encounter neighbouring scent every time they visit their own boundaries.
Other species that are not as exclusively territorial and that tolerate moderate level of range overlap as long as the other individuals stay out of their way and do not deplete their foraging patches, might encounter neighbours’ scent in a more evenly distributed manner on their own range.
It can be beneficial to memorize specific individuals (who do not belong to one’s group) and to be aware of any changes in their status.
Still, this demands for quite some cognitive work and, moreover, what if it also entitles that certain psychological bonds are formed with these frequently smelled individuals regardless of whether it is a desired consequence to being exposed to their scent or not.
But if this is simply an unavoidable nuisance, why would many species also engage in thorough investigations of the scent by neighbours as well as in application of their scent to their own bodies?
I believe that these are curious matters.
For example, my suspicion is that social species who live in social groups and who thereby have activated the respective memory, learning, bonding mechanisms within their groups, cannot really prevent these mechanisms from being enacted also with regard to their neighbours.
The situation, however, is more complicated because animals who do not belong to the same social group and who are territorial, mostly tend to avoid each other.
As a result, scent presence (and perhaps, to a lesser degree, auditory presence) is the main cue that informs the neighbours on each other’s qualities and status including, for example, such status as reproductive or health status.
I believe strongly that animals have empathy for one another and this empathy must be at least partly based on tracking one another’s status throughout time and observing changes in this status as well as reacting to it.
Such observations cannot really be avoided with respect to neighbours, either, and have animals truly succeeded in some behavioural/psychological adaptation which allows them to ‘flip the coin’ and to regard with hostility, suspicion and fear (or triumph and relaxation) what they would otherwise regard with concern, joy, encouragement (or care and worry) in their own social group?
This probably depends on how costly it is to experience joy vs. fear.
If the experience of anxiety and aggression is somehow more beneficial with respect to reading neighbours’ messages than the experience of having sympathy or even joy for them, then animals would have evolved the capacity of ‘flipping the coin’ (to feel troubled or enraged when their neighbours have succeeded to reproduce while the same situation within their own social group might be met with hope, enthusiasm etc.).
Perhaps, early on in evolution, it was beneficial to have these two-sided attitudes to the same phenomenon (even if it meant that the same signal had to be sent along two different pathways which is resource-demanding and perhaps a waste of time/energy/essential compounds).
However, most species have evolved elaborate behaviours to avoid physical confrontations and the stress that accompanies anxiety, aggression etc. might have lost its profit if mortality or serious injury is not a very likely consequence to not experiencing fear and hostility.
An alternative would be that of simply neutralizing (ignoring) the messages left by the neighbours on an emotional level.
Namely, individuals should have evolved a way to engage in emotional responses with respect to specific signals left by their own social group while only processing the information cognitively (in a cool-minded manner) when the signals are left by neighbours.
As emotions are intricately linked with hormones and hormones take part in forming responses to the information that has been processed, individuals would thusly risk leaving out significant portions of data and making wrong decisions (wrong responses).
There is a gradient along which these signals are processed, e.g., when they inform on the identity and status of kin, social affiliate, neighbour, complete stranger.
The difference between these types of social relations is based on the frequency of exposure and the long-term/short-term nature of interactions.
Funnily, it is possible that some social affiliates (who are not met as often as neighbours) might evoke less pressuring response to form bonds than neighbours.
On the other hand, scents are not the only signals used by animals.
The social attachments in one’s group or with one’s allies are augmented by visual presence, more pronounced auditory presence and, importantly, touch as well as a wider array of olfactory cues + taste cues and, not to forget, shared activities as entire experiential assemblies.
Still, I think that this exposure to an abundance of cues serves to familiarize oneself very thoroughly with the individuals closest to oneself (individuals who are allowed to sleep nearby, to allogroom, to play, to forage, to share meals etc.).
As a result, the animal might, in fact, become, in some respects, less concerned about this individual because of the constant presence, the gradual diagnostics of any changes (e.g., if their status changes, it occurs on day by day basis and one might not even notice minor changes, not consciously) and the sense of reassurance that their presence brings (both as something that is familiar and pleasant but also non-threatening as proven by long-term experience).
Neighbours, on the other hand, are far more mysterious, their cues are read less often and with less additional information attached to them, besides, the information processing is of vital importance because neighbours are not necessarily ‘safe’ and their messages can evoke a sense of fear (it is never known what the encounter with the neighbours or even with their scent signals will bring).
Any changes in their status might become experienced in a more sudden and dramatic manner because they are always processed actively and after longer periods of absence.
Thereby, I find it very unlikely that animals are capable of ‘ignoring’ parts of their neighbours’ messages.
My personal opinion is that social species who are also territorial or partly territorial and who have permanent neighbours form bonds with these neighbours; moreover, those are, by character, affiliative bonds despite the outcomes and the apparent rivalry and exclusivity.
I think that, in many cases, animals keep out of one another’s territory not out of fear but out of true mutual understanding based on compassion which has been developed during the prolonged residency as neighbours.
I also think that neighbours are somewhat ‘obsessed’ with one another because it must be very intriguing to read these messages and to create the histories of the individuals/groups leaving them and to, besides, base the learning of the world on comparisons between the familiar experiences (one’s home, social group and neighbours) and unfamiliar experiences (‘the rest of the world’, e.g., non-familiar individuals).
Perhaps the inclination to understand ‘the missing links’ between the last message and the current message is one of the reasons why some species would apply their neighbours’ scent to their own body in order to carry this scent around and to process it longer (in a safer place and perhaps in different experiential contexts) but also to process it in a physically more intense capacity (supplementing the act of inhaling with the interaction of the compounds with one’s skin and one’s own glands).
It is also possible that the story of the neighbours becomes physiochemically intertwined with one’s own story and there could be some evolutionary benefits in processing cues by neighbours because, eventually, the same changes that are affecting neighbours, might affect one’s own group (through shared environment).
Moreover, as I mentioned before, one’s own scent and the scent of one’s group might not always be perceived as consciously if it changes gradually.
As a result, such more gradual, subtle changes might be more easily noticed in the scent left by neighbours because these signals are not read on hourly, minute, second basis but perhaps every few days or less often.
Animals who are capable of processing their neighbours’ scent might have been better able to survive through adapting to present or expected changes.
If, as I have suggested, neighbours actually love one another, why do they chase one another out of their territory and sometimes even fight to death?
I believe that while the immediate reaction to scent signals (anxiety vs. gradual affiliation) is costlier when producing fear/hostility and therefore it might make more sense to allow for much the same pathways to operate the signal processing that ensure the signal processing with regard to one’s social group, the actual response has to be different and it might pay off to evolve a differential response mechanism for neighbours vs. kin/social group.
For example, when one forms bonds with others, they would feel inclined to cooperate, to share, to show concern, to interact etc.
In human societies, it is though that it is always best to pursue such inclinations.
However, human societies have also brought the world to the brink of extinction endangering all life, not just theirs.
For example, the ‘sharing is caring’ concept might have been replaced with some other behavioural response in territorial animals because the very reason behind establishing a territory is that of living within the carrying capacity of one’s environment.
If neighbours felt, at all times, inclined to share, there would be a risk of depleting the resources on both of their ranges leading to starvation, mortality and also to replacement of the neighbouring groups.
It is not known how exactly animals perceive these risks (for example, animals might be aware of the risks through suffering ill-effects from oversharing or perhaps the risks themselves function as natural selection and those who overshare, simply die out) and I will not address this particular aspect at the moment.
I would, however, like to discuss the risks of becoming too fond of too many individuals.
Social interactions with those whom one is bonded with, bring along pleasant experiences and pleasant states which are often hormonal in nature.
However, it is possible that one’s body can only handle as much of a good thing.
Social bonding might have limits in all species (when it is enacted in a manner that involves the apparent responses such as playing together, allogrooming, engaging in other friendly and delightful interactions) because it produces physiological states that the species has not (yet) evolved to handle and that could be detrimental to their survival.
We would encourage a child playing nicely together with another child and laughing and having fun but we would discourage an individual from abusing cocaine or alcohol although both activities lead to increased dopamine levels and are pursued (at least, to some extent) with this specific purpose (to experience altered states of consciousness).
Social interactions that are pleasant and beneficial invoke pleasant and beneficial (relaxing, cheerful, energy-boosting) states.
However, it is possible that if an individual engaged in too many social interactions without accounting for some unforeseen effects (e.g., these interactions were not integrated within long-evolved survival strategies), they might experience states which might bring them harm and lower their chances of survival (in much the same way, consumption of alcohol/drugs can harm us and kill us).
While hostile acts are detrimental, friendly social acts might turn out to be detrimental, as well, and it might make most sense to proceed carefully from having ditched much of physically aggressive confrontations and into making the whole world a big happy family.
Here I should like to note that I do not believe it is impossible but such objectives cannot be taken lightly.
The ‘mysterious’ aspect of one’s neighbours might be beneficial to keep up (not learning too much of them and not becoming too close to them) because the social and territorial individuals might not be prepared to handle the environmental and hormonal/physiological/psychological effects that accompany becoming actual friends and affiliates.
Thus, while the physiological response to signals might be affiliative, the resulting behaviour itself would not be because the lack of familiarity and avoidance might be more beneficial at the current state of social evolution in the species – than a direct pursuit of forming identical relationships one forms with their own social group.
Such avoidance can be achieved through many attitudes such as, for example, respect (not fearing neighbours but respecting them).
For example, the stress of meeting neighbours or having them visit could be founded upon fear but it could be also founded upon the same sense of anxiety we experience when we have more distant friends or relatives come over (vs. our buddies we hang out with every day).
Neighbours have formed long-term opinions of one another and encounters could be rather intense, e.g., cognitively because the mind is actively trying to place the new cues (visual, auditory etc.) with the old ‘database’ pertinent to these particular ‘data entries’.
It could be an overwhelming experience (confirming and countering what has been known and gaining entirely new revelations) and the overwhelming nature of this experience could be used by the species to keep up avoidance because meetings are very demanding on metabolic and cognitive level.
This would be especially true of animals who hold highly exclusive territories (vs. animals whose ranges tend to overlap but who avoid one another) because the degree of isolation and frequency of encounters (as well as the range of cues provided during these encounters) are of significance here.
Animals might not invest into extra-territorial forays without good reason much like we do not spend a lot of money everyday for something that we do not direly need and that might even be upsetting.
Why upsetting? Because affiliation also involves compassion. Knowing the neighbours too closely might cause states which would imperil one’s functioning because then one would be sad, worried etc. about their neighbours, as well.
Perhaps herein lies the ‘mystification’ of neighbours because, in order not to delve into these attitudes upon encountering signs of poor welfare in the neighbouring group, the individual might have to assume an attitude that the neighbours are perhaps different than the individual and their social group and that they have other ways of dealing with hardships.
This could be assisted by the sudden nature of gaining insights into the events of the neighbouring group because, without tracing the developments day by day, the individual might think that the neighbours are capable of somehow miraculously fixing their troubles (because last time there was a problem and now it is gone, while in one’s own group, troubles seem to persist ‘forever’).
Additionally, one might not be as physiologically affected by neighbouring distress signals (and cues indicating of their success) because one is not as adapted to daily living side by side with the neighbours.
Thus, the intensity of response could be lesser but, also, one might feel as if the neighbours are somehow ‘alien’ because they sort of demonstrate the same life patterns (as one can recognize on one’s own group) but they do not elicit the same physiochemical responses (which might be perceived as them being different rather than the response mechanism being different).
It is still difficult (also for me) to explain some of the acts that territorial species commit toward their neighbours and how they could be rooted in affiliation rather than competition and hate/fear.
For example, why do neighbours sometimes kill one another or kill one another’s offspring?
Why would they seek to expand their own territories at expense of their neighbours?
These are complex behaviours but I still believe that they are rooted in affiliative bonds but they become translated into responses that, as humans, we have long since forgotten to associate with care, compassion, concern and respect.
Animals have had to learn to respond to different social situations with different hormonal/physiological reactions not to surpass their own metabolic and environmental limits.
Still, these social responses might have been evolved to demonstrate engagement and concern but through entirely different physiological pathways.
Perhaps the intensity in neighbouring relationships, in some species, might be the result of the intensity of the bond they have actually formed which translates into dramatic responses.
To conclude, I would like to state that some of the apparent ‘hostility’ between captive individuals who have been brought together with the intent of enticing them into formation of a socially bonded group, could be the result of such associations not having formed very naturally (through kin, mate selection mechanisms) and these individuals, thereby, at first, perceive one another as neighbours.
But, as we have just theorized, neighbours might bond in a manner which does not appear friendly to a human observer.
In fact, I suspect that captive animals have performed an astounding achievement of overcoming the very evolution because they have succeeded at moving on from the necessary and survival-promoting distancing (a type of social bond formed with neighbours) to the type of bonding observed in social groups that share their physical space, their time and their activities on everyday, every-minute basis.
It is a sadness these captive animals cannot return into the wild to teach their finding to the rest of the individuals in their species.
Finally, I would like to point out that because humans believe in the paradigm of neighbours = competitors (in animal species), our science does not actively evaluate whether such neighbours are or are not considerate of one another in an affiliative, respectful manner.
For example, while extraterritorial forays are easy to report, it would be much harder to assess on how many occasions an individual/group has refrained from intruding into their neighbours’ territory (despite perhaps great necessity).
Moreover, it is currently impossible to discern the motivations (are they afraid to intrude or do they not wish to aggravate the neighbours?).
We are not searching for manifestations of neighbourly love in animals and we are searching for manifestations of what we think of as neighbourly competition but, in science, it is known that the searching effort affects the analytical outcome.
Notes by Ieva 