Songbirds & Honeybees: Reprioritizing Welfare Based On The Experience Of Time
Packaged in neat parcels of hours, days, and seconds, time feels regimented and real. It’s easy to forget that these divisions are simply helpful fictions, created by humans to structure our own sense of time. The span of time that, to a human seems to pass in one second, might seem to last much longer (or conversely, to elapse far more quickly) to another species. This concept is known as the subjective experience of time, and it has significant implications for how we prioritize welfare across species. In this forum post, the author discusses the concept of the subjective experience of time, considers how we might measure and compare it, and explores its consequences for welfare prioritization and resource allocation.
Before looking at the evidence, it’s worth preempting an easy misconception. Time flies when you’re having fun, but in a different way from an accelerated subjective experience of time. In the first case, having a good time creates the illusion of speed, but time isn’t itself distorted. To use the author’s example, reality doesn’t suddenly move like a video on fast-forward. In contrast, mind-altering drugs and life-or-death situations might alter one’s subjective experience of time, compressing or dilating the apparent flow of time.
Reports from humans about time distortion under such conditions constitute one form of evidence in favor of the subjective experience of time, but these reports alone are not wholly convincing. Time might seem to slow in a life-or-death situation, but it may be that the tension heightens a person’s senses, so that the incident is more deeply stamped on their memory. The unusually high definition of the memory might then create an illusion that time passed more slowly.
As scholars still disagree about what’s going on in human reports of situational time distortion, we need to look for other possible sources of evidence. The author explores several other indications. For one, given the enormous diversity across species, it’s not unbelievable that species may experience time differently. Electric eels interpret their environment using electricity, bats echolocate, and some beetles can detect heat. Evolution exploits any possible advantage, and for a prey animal evading the jaws of a predator, a faster subjective experience of time seems a clear benefit.
Animals such as hummingbirds have extraordinarily fast reactions. Depending on whether these are consciously controlled or simply reflexes, the lightning-quick reaction times of a hummingbird’s flight might demand an accelerated subjective experience of time. Birdsong offers even more compelling evidence, as it is more plausibly consciously controlled than reactions in flight. To process and respond so quickly to the songs of their fellows, songbirds may need to experience time at a faster subjective rate.
Studies of vision across species offer another piece of evidence for subjective time. Critical flicker-fusion frequency (CFF) is the point at which a flickering light source appears to blur into a continuous stream. Animals with a high CFF receive higher rates of information from the environment per unit of time; this may reflect a higher subjective experience. (As the author notes, it’s important to recognize the inevitable bias of this measure toward animals for whom vision is their primary sense.)
As well as providing some evidence that different species experience time at different rates, CFF may offer insight into the variance. The author provides twelve other such proxies for the subjective experience of time, which he groups into neurological, behavioral, and temporal resolution measures. Respectively, these grouped proxies indicate how quickly signals move through an animal’s central nervous system; how quickly an animal responds to events in their environment; and how frequently an animal’s perceptual system takes in information. Such proxies can be useful to quantifiably compare subjective experience of time across different species.
Some examples may be helpful to understand these proxies. One neurological measure is interneuronal distance, or the space between neurons. Shorter distances between neurons means faster communication, and so may allow for a faster subjective experience of time. Touched on above, reaction times may be a potential behavioral measure. Finally, temporal resolution measures include CFF and its equivalents for other senses, such as auditory flutter-fusion thresholds (high among dolphins, for instance).
Assuming that the subjective experience of time does vary across species and can theoretically be measured through proxies, let’s turn to the implications. The broad ethical issue is this: With limited resources available, metrics are a useful tool to help us decide which species to focus on. But which metrics are appropriate?
The subjective experience of time remains understudied, and the author acknowledges that a lot more research is needed to integrate the concept into our moral framework. But in the meantime, we should scrutinize the metrics in use today to prioritize species, and ask ourselves whether their encoded values sufficiently capture what is morally relevant.
Currently, measures like IQ, neuron count, and the ratio of brain to body mass are used, founded on the idea that higher complexity and intelligence is linked to higher moral worth. In contrast, the subjective experience of time presents a different possible way to measure moral worth – one that comes out with a very different hierarchy of priorities. Instead of great apes, honeybees look most in need of our attention.
Much of this discussion may seem mindboggling and counterintuitive. We’re so used to prioritizing the smarter species that the welfare of insects barely crosses our minds. But if one being experiences a second of pain as passing in the blink of an eye, and another, as dragging out over an age, shouldn’t we try to prevent that second of pain for whomever experiences it as interminable?
So, as animal advocates, should we focus more on songbirds and honeybees? If we accept the evidence in favor of the subjective experience of time, the answer might be yes. But for the unconvinced, the subjective experience of time can nonetheless act as a reminder of the extraordinarily diverse ways of being an animal alive in the world. No matter our moral conclusions, there’s wonder in that.