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One of the things that became really apparent to me during a brief period of dating a hearing-impaired person, was the utility of sign language as a supplement

One of the things that became really apparent to me during a brief period of dating a hearing-impaired person, was the utility of sign language as a supplement to spoken language. Sign language works better than speech in noisy environments. But this drew my attention to situations where sign language doesn't work: in the dark, around obstacles, when hands are occupied. Guess which situation our ancestors were more frequently confronted with? EDIT: The article does address this, but I'm not sure I buy it. Maybe it's a function of my limited ability with sign, but I don't think signs pressed against the skin are particularly effective, and while our ancestors may have had fires, the most survival-critical situations could be ones where no light is present. I agree that sign remains extremely useful, but I'm skeptical of the claim, "[I]f language had first built a home in the hands, it would have had no compelling reason to leave. Thus, it must have been spoken from the start."

James_Henry 6y ago
The article talks to this. "A second supposed advantage is that speech is better in the dark – that, as Levelt put it, gesture is ‘functionally dead during, on average, 12 hours a day’. This is probably overstated. As Emmorey points out, modern signers get by without much problem, even in dim lighting, and can use tactile forms of signing – that is, signing in contact with another’s skin – in a pinch. Our prehistoric ancestors likely didn’t spend many waking hours in pitch-black. Rather, they would have used fires for warmth, cooking, illumination and protection from predators. And, whether or not there’s anything to Hewes’s palmar depigmentation story, hand movements can certainly be seen by firelight. "Another advantage of speech, it has been argued, is that it frees the hands for other activities. But, here again, this is likely too swift. Signers don’t seem to have much of a problem with this, using one-handed signs when necessary. And though most of what we think of as gesture takes place in the hands, critical visual signals can also be produced with the head and face – pointing, affirming, questioning. The list of putative advantages of speech goes still further. But this kind of ‘rear-view mirror’ reasoning is inherently shaky: we know the outcome and are motivated to explain it."
- ceejayoz 6y ago
  > But this kind of ‘rear-view mirror’ reasoning is inherently shaky: we know the outcome and are motivated to explain it." The other side of this, though, is there's presumably some sort of reason, and these ones are plausible. We should be open to more compelling hypotheses, but waiving away "it's good to have two hands free" with "you can sorta get by with one" is "inherently shaky" too. Stuff like grinding corn and butchering game are two-hand jobs, for example. It helps to be able to chat while you do it.
  - kerkeslager 6y ago
    I think you're misunderstanding what the article is claiming. It's not claiming, "Language started in the hands, but we don't know why it left the hands." It's claiming, "We can't be sure that language started in the hands, because we don't have an adequate explanation for why it would have ever left if it started there." Put another way, this article is summarizing the "started in the hands vs. started in the mouth" argument. The article is very much not on the side of "language started in the hands".
  - kqr 6y ago
    Grinding corn and butchering game are also activities that would be relatively uncommon for the foraging humans that started communicating with more complexity.
- tgv 6y ago
  Speech must have evolved before cooking.
SilasX 6y ago
Naive question: I thought seeing in the dark was easier pre-electricity because there was no “light pollution” and everything was lit up uniformly, so you could see well enough outdoors once your eyes adjusted, based on moon- and starlight? That is, above some threshold, the main barrier is contrast, not dimness?
- kerkeslager 6y ago
  That's a good question, and not one I know the answer to. I've spent a good amount of time out in nature in the dark, in areas with very little light pollution. In these areas, moonlight can definitely be adequate for a lot of things. But under tree or cloud cover, or when the moon is new, the natural dark can be truly debilitating. Now, this could be because my modern vision system never properly adjusts because it's used to light pollution, but I'd at least conclude from this that a lack of light pollution doesn't inherently mean better night vision.
- tgv 6y ago
  Then you should be able to see even better now, since there is more light. The places I've visited where light pollution is low, are really, really dark at night.
  - SilasX 6y ago
    Maybe my point wasn't clear? To the extent that we have difficulty seeing unassisted in dark today, it's because: 1) There are many artificial sources of light, which creates a sharp contrast. If the stuff near those sources is illuminated, everything else becomes harder to see. 2) You spend very little time outside, so even when there isn't a sharp contrast, you haven't waited for your eyes to adjust. Obviously, given artificial illumination where we want it, stuff is easier to see. See sibling reply about navigating by moonlight remote places.
    - tgv 6y ago
      Ad 1. Background light pollution doesn't create a sharp contrast. But it's irrelevant, since that's something so recent that it can't have any influence on this topic. 2. Where it's really dark, you can't see. Period. No amount of waiting will help.

James_Henry 6y ago

The article talks to this. "A second supposed advantage is that speech is better in the dark – that, as Levelt put it, gesture is ‘functionally dead during, on average, 12 hours a day’. This is probably overstated. As Emmorey points out, modern signers get by without much problem, even in dim lighting, and can use tactile forms of signing – that is, signing in contact with another’s skin – in a pinch. Our prehistoric ancestors likely didn’t spend many waking hours in pitch-black. Rather, they would have used fires for warmth, cooking, illumination and protection from predators. And, whether or not there’s anything to Hewes’s palmar depigmentation story, hand movements can certainly be seen by firelight. "Another advantage of speech, it has been argued, is that it frees the hands for other activities. But, here again, this is likely too swift. Signers don’t seem to have much of a problem with this, using one-handed signs when necessary. And though most of what we think of as gesture takes place in the hands, critical visual signals can also be produced with the head and face – pointing, affirming, questioning. The list of putative advantages of speech goes still further. But this kind of ‘rear-view mirror’ reasoning is inherently shaky: we know the outcome and are motivated to explain it."

ceejayoz 6y ago
> But this kind of ‘rear-view mirror’ reasoning is inherently shaky: we know the outcome and are motivated to explain it." The other side of this, though, is there's presumably some sort of reason, and these ones are plausible. We should be open to more compelling hypotheses, but waiving away "it's good to have two hands free" with "you can sorta get by with one" is "inherently shaky" too. Stuff like grinding corn and butchering game are two-hand jobs, for example. It helps to be able to chat while you do it.
- kerkeslager 6y ago
  I think you're misunderstanding what the article is claiming. It's not claiming, "Language started in the hands, but we don't know why it left the hands." It's claiming, "We can't be sure that language started in the hands, because we don't have an adequate explanation for why it would have ever left if it started there." Put another way, this article is summarizing the "started in the hands vs. started in the mouth" argument. The article is very much not on the side of "language started in the hands".
- kqr 6y ago
  Grinding corn and butchering game are also activities that would be relatively uncommon for the foraging humans that started communicating with more complexity.
tgv 6y ago
Speech must have evolved before cooking.

SilasX 6y ago

Naive question: I thought seeing in the dark was easier pre-electricity because there was no “light pollution” and everything was lit up uniformly, so you could see well enough outdoors once your eyes adjusted, based on moon- and starlight? That is, above some threshold, the main barrier is contrast, not dimness?

kerkeslager 6y ago
That's a good question, and not one I know the answer to. I've spent a good amount of time out in nature in the dark, in areas with very little light pollution. In these areas, moonlight can definitely be adequate for a lot of things. But under tree or cloud cover, or when the moon is new, the natural dark can be truly debilitating. Now, this could be because my modern vision system never properly adjusts because it's used to light pollution, but I'd at least conclude from this that a lack of light pollution doesn't inherently mean better night vision.
tgv 6y ago
Then you should be able to see even better now, since there is more light. The places I've visited where light pollution is low, are really, really dark at night.
- SilasX 6y ago
  Maybe my point wasn't clear? To the extent that we have difficulty seeing unassisted in dark today, it's because: 1) There are many artificial sources of light, which creates a sharp contrast. If the stuff near those sources is illuminated, everything else becomes harder to see. 2) You spend very little time outside, so even when there isn't a sharp contrast, you haven't waited for your eyes to adjust. Obviously, given artificial illumination where we want it, stuff is easier to see. See sibling reply about navigating by moonlight remote places.
  - tgv 6y ago
    Ad 1. Background light pollution doesn't create a sharp contrast. But it's irrelevant, since that's something so recent that it can't have any influence on this topic. 2. Where it's really dark, you can't see. Period. No amount of waiting will help.