05/25/2024
NEOTENY IN DOGS: FOREVER YOUNG, FOREVER AFFECTED
Neoteny, also known as juvenilisation ( retention of juvenile characteristics in adults) is a significant concept influencing every dog today. Neoteny essentially refers to the 'delaying of development' in an animal. Scientifically speaking , many species, including humans, have undergone neotenisation through evolutionary processes by selecting specific traits in both behaviour and physical characteristics. There is a distinction however, between Neoteny which is adaptive ( macro-evolutionised) and paedomorphism which is evolutionary (sometimes used interchangeably) In other words, Neoteny = retention of juvenile characters by adults and Paedomorphism = reproduction by a juvenile.
Neoteny is also well-documented in the domestication of dogs. For example; selecting for specific motor patterns of predatory sequences in herding breeds, or selecting of behaviour traits in livestock guardians. Over millennia, dogs have transitioned from being primarily working animals to modern pets kept mainly for companionship and breeding practices have adapted to meet the demand for increasingly cute-looking animals. More recently, we have seen breed standards changed significantly to favour neotenised physical traits.
Common neotenous physical traits in domesticated animals (such as dogs, pigs, ferrets, cats, and even foxes) include floppy ears, changes in the reproductive cycle, curly tails, piebald colouration, fewer or shortened vertebrae, large eyes, rounded foreheads, large ears, and shortened muzzles. Juvenile behaviours are also selected to facilitate domestication, as aggressiveness typically associated with adulthood is undesirable. Selecting for juvenile behavioural traits can in turn lead to neoteny in physical characteristics because reduced aggression negates the need for physical traits that support aggressive behaviour, such as a developed muzzle and larger size. Moreover, in dogs a prolonged and slower juvenile period allows for greater plasticity and higher trainability compared to wild relatives.
Breeds like the Cavalier King Charles Spaniel, Pekingese, Pug, and French Bulldog are said to be highly neotenised, though all dog breeds exhibit degrees of neoteny. This phenomenon is correlated with human preferences for ‘baby-face’ or infant like dogs, and feelings of affection toward animals with juvenile features. Perhaps this might be a feature of our own neoteny?
There continue to be implications of neoteny for modern dogs that warrant our consideration:
• Impact of Spaying and Neutering: Considering that dogs are already neotenised, how does spaying and neutering affect them? While further neoteny can’t occur because the animal can’t pass on genes through breeding, the removal of s*x hormones especially before their already neotenised s*xual maturity phase raises several questions, from impact on musculoskeletal development, forming of fears and even increased aggression.
• Animal Welfare: Neoteny’s impact on welfare is notable, especially in brachycephalic breeds like Pugs and French Bulldogs. But, there are also concern for breeds bred for ‘biddability,’ such as Labradors or Malinois, bred for intense work. Other examples are dogs bred for 'teddy bear' looks or extreme miniature dogs. Sports or other such activities in pet dogs can also be considered, as neotenised traits likely play a role in the animals' cooperation and enthusiasm. In all groups, both physical and emotional consequences are important to consider.
• Ecological Costs: The ecological costs of neoteny on animals are also significant. Consider pet dogs vs free ranging dogs. Pet dogs face unique challenges in their day to day lives, from navigating rapidly changing environments, adherence to arbitrary human laws, meeting members of their own species in an endless array of sizes , shapes, ages and s*xual characteristics, both on lead or off lead. Overall pet dogs seem to fare well despite these conditions and it would be fair to say that neoteny is likely to have played roles in interactions of conflict, predation as well as positive affiliation.
In the free ranging dog ecology, rapid urbanisation in some regions are decreasing their habitat and food availability. Many areas are now being subjected to vigorous spay and neutering programs in order to reduce numbers but there are reports that these programs are causing some animals to become aggressive and disrupting their social groups might have increased bites towards humans. This is problematic because in many of these countries, rabies has not been fully eradicated. Further selection pressures are coming from humans breeding pet dogs, which are also following a neotenised trend. Conflicts between pets and free ranging dogs are on the rise as a result and there is a growing bias toward selecting smaller and cuter looking dogs as pets.
In the age of information, social media has further popularised neoteny, as seen in the frequent appearances of such traits on our feeds creating a bias toward some characteristics. However, breeds less physically neotenised such as German Shepherds and Malinois are being used for high energy work, performing repetitive sequences, in contrast other breeds are dressed in clothing to make them look more endearing.
A recent article titled “Peter Pan Pups” published April 2024 (link in comments) highlighted data from 22 million dog insurance claims, revealing that many adult and senior dogs of certain breeds exhibit increased risk of injuries typically associated with juvenile behaviour (such as ingesting inedible objects and physical trauma)
The breeds identified in the article included:
• English Bull Terrier
• Bernese Mountain Dog
• American Bulldog
• Greyhound
• Belgian Malinois
• Airedale Terrier
• German Shepherd
• Weimaraner
The data ( Nationwide, USA) they suggest is that ‘juvenile’ behaviours are being retained on a large scale, indicating a potential cause and effect. More scrutiny into the data might reveal causal links, as neoteny itself is likely to not be the driving factor , perhaps early spaying and neutering could be looked into; or how breeding practice in the USA might influence data in the context of this. There could be several other reasons also.
Because Insurance companies often increase premiums due to rising claims and may decrease premiums for neutered animals, it seems controversial if there is a direct link to neutering and retained juvenile behaviours. It is interesting to note that the breeds listed as retaining juvenile traits are predominantly less physically neotenised than others.
We can consider the ongoing issues with neoteny as an intensification of selection pressures on not only domesticated dogs but on humans by proxy.
Although we have limited control over neoteny itself, understanding its impact and engaging in informed discussions might inspire a shift in overall perspective, leading to improved breeding and welfare outcomes.
Boo Blackhurst, CDBC
Resources:
H.B. Shaffer,Neoteny, Brenner's Encyclopedia of Genetics (Second Edition),Academic Press, 2013, Pages 26-27
B.T. Shea,Paedomorphosis, Brenner's Encyclopedia of Genetics (Second Edition), Academic Press, 2013, Pages 209-212
McGreevy PD, Wilson B, Starling MJ, Serpell JA (2018) Behavioural risks in male dogs with minimal lifetime exposure to gonadal hormones may complicate population-control benefits of des*xing.
Borgi M, Cirulli F. Pet Face: Mechanisms Underlying Human-Animal Relationships. Front Psychol. 2016 Mar 8;7:298.
Coppinger, R. & Glendinning, John & Torop, E. & Matthay, C. & Sutherland, Michael & Smith, Charles. (1987). Degree of Behavioral Neoteny Differentiates Canid Polymorphs. Ethology. 75. 89 - 108.
Koops, W.. (1996). Historical Developmental Psychology: The Sample Case of Paintings. International Journal of Behavioral Development - INT J BEHAV DEV. 19. 393-413.
