Why Only Humans Talk

These charming spinner dolphins turn out to be as lethal as a wolf pack and twice as group oriented. (Photo from Oregon State University.)

A meditation on dolphins has gotten me to come at speech origins from a fresh direction and made me see again how amazing it is that our lineage ever hit upon language.

I have never been much of a dolphin enthusiast, but an interesting report an account of dolphin cooperation in feeding has been published in the Acoustical Society of America journal (press release here) and adds a twist to a recent post (see: On Being Human). Could it be that dolphins are more human than the apes are?

The premise of the earlier post was that humans are uniquely smart enough to adapt as a group, knowing that we do best if we face our problem together. In this view, speech evolved as part of the process of enabling members of the human lineage to develop a sense of unity with others. The post also argued that cooperative-seeming activity during a hunt by chimpanzees does not really reflect a group adaptation because the chimpanzees do not have a shared goal. Each wants the food for himself, not for the group. An account of hunting by spinner dolphins is more provocative. According to a press release from Oregon State University:

Initially a small group of about 20 dolphins would swim side-by-side in a straight line until finding concentrations of prey – in this case, lanternfish. When they got to within five meters of their prey, they would pull into a tight circular formation and sequentially swim up and down vertically, in essence, doing "the wave" like fans at a sporting event… As the lanternfish became concentrated, the dolphins tightened their circle and formed 10 pairs. The pairs at one o'clock and seven o'clock would move in, feed for 15 seconds, and retreat back to the circle. Then the pairs at two o'clock and eight o'clock would do likewise.  The feeding would last for about five minutes, during which time each dolphin got two opportunities to feed, and then the group rose as one to the surface to breathe, maintaining their circle. The dolphins would take one breath … and then dive down and begin the process anew.

The most intriguing part of this description is the waiting one’s turn. That action seems to imply a shared goal of group eating and is markedly different from the smash-and-grab free-for-all that is typical of much predator behavior, including that of chimpanzees.

The dolphin’s hunting takes place at night, below the water, so the spinner dolphins cannot coordinate by sight.

Dolphins are often vocal and their use of frequency-modulated whistles was thought by many to cue their coordinated behavior. But the researchers found they didn't use those whistles at all while hunting prey – just during non-foraging times or when they were surfacing. Instead, they used a series of "clicks," with the highest click rates taking place just prior to foraging. "Whistles are omni-directional, like turning on a light bulb in a room," [the study’s lead author, Kelly] Benoit-Bird said. "Clicks, on the other hand, are directional like a laser. We think it may be a strategy to communicate only within the group and not to other potential lanternfish predators. Tuna and billfish are looking for the same prey and they can hear the whistles but not the clicks because the frequencies are too high and so focused.

This distinction between broadcast squeaks and local clicks reminds me of a recent post in which the same broadcast/proximal distinction was made between chimpanzee cries. (See: Ape Cries Are Complex) Obviously, more has to be understood, but the Acoustical Society’s report continues a tradition of finding real cooperation among dolphins. Taking turns to reap the benefits from a common goal would seem to constitute true cooperation.

So what happens to the idea that humans are unique because we face our problems together? I suspect that now that the idea of group selection is becoming acceptable again, biologists will recognize many examples of this kind of sharing. I have seen African buffalo work together to chase lions away from a herd, an action in which individuals put themselves at real risk for the benefit of the group. African elephants and parrots are two more species where close study might pay rich rewards in group-behavior research. Group selection implies shared benefits, and although kin benefits are likely to always predominate, examples of shared benefits are probably going to be more common now that biologists have thought to look for them. 

I am used to asking on this blog that we know the great apes are smart enough to use at least some language, so why don’t they. The answer is they are not group-oriented, have no sense of we. Now we have to flip that puzzle around. Dolphins appear to have enough of a sense of we to have at least some language, so why don’t they. And the answer is likely to be that they are not smart enough.

I have to be more cautious when considering dolphins for the simple fact is that we don’t know, or at least I don’t know, as much about dolphins as we (I) do about primates. 

Do dolphins have language? I doubt it. They communicate, but just about all mammals communicate. Language is different. On this blog speech coordinates joint attention for purposes of mutual perception. Do dolphins do that? Until I am shown that they do, I will assume that they do not. The press release has an interesting account of clicks rising to a climax just before feeding. They might be communicating, might be echolocating, might be doing something I can’t imagine. Since they are all making the sounds together, they do not appear to be talking.

Is the dolphin’s group activity the result of intelligence or natural selection? Since natural selection is the simpler explanation, I’m going with that until shown otherwise. Investigation seems unlikely to establish that dolphins figured out this maneuver by themselves or that they continue to adapt to their circumstances in a creative way. The same holds for African buffalo. Their joint attacks on lions that come too close are probably not creative adaptations.

Dolphins, buffalo, and most animals do not have much opportunity to become intelligently adaptive. They lack organs, notably hands, that can be used to manipulate the environment in novel ways. Primates have hands and with them came the opportunity to find new things to do. Dolphins and buffalo do not have such things. (Elephants with their trunks may be a different story.)

I confess to never having thought it about it clearly before, but apparently after apes were forced out of the trees and before they had become upright bipeds they had to adapt by using their hands, maybe digging up roots or finding new insects to eat. Dolphins don’t have any organs that would permit such ad hoc flexibility.

So it looks like the evolution of language required two contradictory threads: creative intelligence and  a sense of we. I say contradictory because each thread pushes against the other. Intelligence provides advantage to the smarty pants with the clever insight and subverts group identity while a sense of we undermines the personal ambition that makes creative thought fruitful. The human condition is characterized by an I-we tension that underlies all comedy, tragedy, and moral quest. Every attempt to end the tension by choosing one side of the other leads to a dystopia, but riding the surfboard through the waves is hard to maintain. Evolution cannot find the task any easier than we do.

I have to be careful here. I don’t want to fall back on Dr. Johnson’s solution and say the evolution of speech was a miracle, but it does look highly improbable, requiring as it did the coming together of two unlikely and mutually antagonistic evolutionary lines.

Comments

[Dolphy Dolphin]

Yeah; we've been chattin' it up for years.....

[Chris]

Mind in the Waters: A book to celebrate the consciousness of whales and dolphins

[Flipper]

click click whistle click click click whistle click whistle click click

[Flipper]

No but on a serious note, have you factored in thoughts on the possibility that language was an evolution of synesthetic nature? Not sure if that would make a difference. Haven't really thought it out myself.

You crazy humans and your 5 senses.
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BLOGGER: Synesthesia is a combining of sensual qualities. For example, a person might hear a sound and not only hear the sounds but see some kind of color patterns as well. I'm not sure what "synesthetic nature" might be unless it merely refers to the way nature can trigger many senses at once.

It is true, by the way that language can be synesthesic if you mean that a sentence can draw attention to more than one sense at a time: e.g., "That flute sound is very bright, while the accompanying cello is much darker."

It is probably also true that a single sensation by itself is meaningless, e.g., upon entering a house a person might sniff something, but only know what he is sniffing because the smell evokes an image of spaghetti. Language may short circuit this process, so that instead of evoking the image the smell evokes a word and we know the name of what we smell.

In short, Flipper's comments may seem flippant but there is much to ponder here if you care to riff on it.

[James Winters]

Slightly related is Ramachandran's synesthetic bootstrapping theory of language origins: http://www.weaverluke.com/blog/2005/05/ramachandrans-synesthetic.html

I'm not convinced by Ramachandran's account, but there might be some merit in expanding upon cross-domain remapping -- especially in accounting for language. Just thought I'd put this out there for curious minds.

[Robert]

The have made an error in understanding sonar use in hunting. The whistles are obviously communication , the clicks a simply hunting sounds, what people forget is unlike sight, when it comes to sonar all members of the hunting pack can 'see' each others focus on targets as well as each others position relative to the targets, in this case sonar gives them 3d vision of themselves and their environment. So discussion before to set tactics then switch into shared hunt mode.

[ejes]

just cause you can't understand them doesn't mean that all animals don't communicate with eachother - even if it's non verbal.