Design Synthesis' Johnny Pi asks:
I was thinking about a turtle I once had. I don't recall ever seeing it engage in play-behavior. None of my experiences with reptiles/amphibians ever yielded any strong impression of behavior that even appeared to be play... Perhaps some human apprehension toward reptiles/amphibians stems from lack of recognizable patterns. Maybe they do play, but the behaviors are so distant from our own experience that we don't recognize them. Anybody have any knowledge on this topic?
The post includes some rough explanations, which I'd like to comment upon:
1. Cold-blooded animals must conserve energy more than mammals/birds. They cannot afford to engage in seemingly-superfluous behaviors.
I tend to concur that the need to conserve energy is a factor here, but I suspect that if cold blooded animals do play it may be harder to spot because of their method(s) of thermoregulation. For instance, a turtle might enjoy riding a strong ocean current (a low energy expenditure activity), but how would we know if they were choosing to do so for play?
2. Reptiles/Amphibians do not commonly form social structures or engage in nurture behavior. The ones that do (alligators, I believe, may spend time with their young) often nest in isolated areas only now being monitored by researchers.
Crocodiles and alligators have been observed in great detail by, for instance, Steve and Terri Irwin (The Crocodile Hunter) in environments which should be sufficiently similar to their wild habitats that if there was play to be reported, I believe we would have heard about it. (Although see the counterargument below).
Also, why would social structures and nurture behaviour be prerequisites for play? Whilst many theories of play provide social benefits to play, there are plenty (including play as learning) which do not.
3. Brain structure? Not geared toward pattern-recognition or memory.
Every multicellular creature has brains geared towards pattern-recognition - that's the one thing we can be confident the brain does. However, I do think that brain structure might be a key factor.
The notorious sceptic Carl Sagan observed that there is a section of our brain,
which is morphologically and functionally similar to a reptile brain,
embedded in our brain stem, called the "Reptilian Complex". In his view, mammal brains are a next generation of cerebral hardware - an upgrade to the reptile brain, if you will. The reptile brain is a basic cerebral processor - it behaves instinctively on the signals it receives. But it is relatively simple in its construction compared to our brains.
The mammal brain is Brain 2.0 - it adds neurotransmitters and hormones that add the complete emotional layer to life. It's my broad contention that much of what we call play is associated with the hardware of the mammal brain. Play thrives on being entertaining - without such emotions, there is no enjoyment, per se.
Sagan believed that the human brain was Brain 3.0, its neo-cortex allowing for objective processing of data and experience. I do not concur. I have spent considerable time observing mammals and birds, and I'm not greatly convinced that the human brain is a step up at all. Were it not for language (and the related capacity to store data extrogenously) I'm not convinced there would be any significant difference between humans and many other mammals, including dolphins, apes and elephants. For all that science successfully dismantled humanocentric thinking in such areas as the structure of our solar system, there are still too many scientists who want to place humans in a different class to other life - a convenient means of dissipating cognitive dissonance caused by our cruelty to animals, perhaps...
That aside, I suspect that brain structure is a primary factor in why we don't observe play in reptiles. The reptile brain is a powerful tool - but it's basically a signal processor, with none of the sophisticated emotional programming of the mammal brain. I suspect that emotion is a requirement for play - although we might be premature in suggesting that reptiles do not have some emotions.
4. Aforementioned unrecognizable play structures.
This brings me to the other side of the coin. Wittgenstein said: "If a lion could talk, we would not understand him" (Philosophical Investigations II, xi, p. 223). What the philosopher was getting at was that even if we could understand the referents of a lion's words (that "roar" means "zebra", and "rar rar roar" means "Make mine a zebra burger") we would still have no basis for understanding lion ethics, politics, humour, religion, aesthetics and so forth, because true understanding requires empathy bourne of similarity of experience. It is questionable how well we achieve this with other human beings much of the time, let alone with another species.
The lesson here is that even if turtles do play, we might have no way of recognising it as such. They stack themselves in piles for basking, but we have no way of knowing if participating in a turtle stack is fun. If emotion is related to the limbic system (which is a commonly espoused view), then fish, reptiles and amphibians may have emotions, albeit different emotions to those of the animals with neurotransmitters and hormones.
Like so much of science (and despite the strenuous objections of scientific fundamentalists), there is a boundary of belief: science does not uncover big-t Truth, but merely reports the results of observations, experimental or logical. Ultimately, it is up to the individual to decide what they believe. No-one believes the results of every scientific experiment - half of them contradict the other half, after all! We decide which results we permit into our belief system. It's part of what makes each of us an individual.
Do turtles play? What do you believe?