In Homo Sapiens the males generally have much more upper body strength than females and also advantages in lower body strength as well.
Has this always been true of Human species? Did Neanderthal females suffer under similar disparities, or was it more equal. What about primates generally?
I believe the dimorphism is smaller in nonhuman primates, and a female chimp is much stronger than a normal human male.
Wikipedia on primate dimorphism (wow a whole article!)
Article
Cecil
What about non Homo Sapien humans?
Don’t know about hominids, but certainly holds true for most apes - to an even greater-than-human degree in e.g. Gorillas and Orangs, but also in chimps and bonobos (but not, IIRC, in gibbons) and also in other primates like baboons. So I’d say it’s likely to hold for hominids too.
As I recall we’re middling. It seems to be related to how prone the species is towards a one-male-and-a-harem lifestyle; the more a species tends that way the bigger the males tend to be relative to the females, since they have to be big to fight off rival males.
Here’s a table, but it doesn’t cover other Homo species.
http://www.geo.arizona.edu/Antevs/nats104/00lect13dimorph.html
The wikipedia article on Homo Erectus briefly mentions dimorphism:
Not really - Gorillas, for example, are way more dimorphic than humans.
True, but irrelevant, as male chimps are that much stronger again.
We are prone to that as well. Whats stops us is the fact we are complex social animals and having a large population of unmarried males in problematic. So I really doubt this.
Has there been any work on diamorphism in other human species?
Wikipedia needs to read itself. 
From the article on Australopithecus:
It’s more complicated than that. Gorillas have harems, but chimps don’t. Chimps are promiscuous, even if the alpha male does try to hog all the females. Also, Orangs lead largely solitary lives. Larger males usually means there is more competition for females, but doesn’t necessarily mean harems are created.
Although I’m not going to say you’re wrong, I will say that’s not a factual statement. It could certainly apply to chimps as well, and they seem to be able to manage. Humans are incredible less violent in our day-to-day lives than chimps are, so if anything it might be LESS of a problem for us. Imagine a sports stadium full of hoo-man animals and now imagine that it was an equal number and density of chimps. The latter would be the chimp equivalent of WWIII within a matter of minutes.
Chimps are no where near as socially complex as we are. Don’t discount the effects of that. W are less violent because we have less cause to be, and social groups punish/clampdown on attempt to limit violence as much as possible. Its interesting, but murder, theft and rape are crimes recognised by pretty much ALL peoples, from moonwalking Americans, to primitive Hunter gatherers. Basically any complex human social group. These are three things which manifest themselves heavily when violence is the norm.
That sounds awesome. How much to make it happen?
The degree of sexual dimorphism is often linked to the extent of male-male competition for females. In gorillas, fur seals, deer, etc. males are much larger than females because dominant males defend harems and get most of the matings. In species which are mostly monogamous the sexes are often not dimorphic in size.
The decreasing sexual dimorphism in the human lineage from Australopithecus to Homo erectus to H. sapiens has been attributed to a trend towards a more monogamous mating pattern. It is thought that the large degree of dimophism in Austrolopithecus indicates that males may have defended harems like gorillas. Modern humans show a moderate degree of sexual dimorphism, and in many traditional societies are somewhat polygynous, with dominant males having several wives.
This hijack might be outside the scope of the OP and this thread, but what about animals where the sexual dimporphism goes the other way? For example, many birds of prey (falcons etc.) have larger females than males within a particular species. No harems there – not even “reverse” harems 
– so what drives that?
Again, apologies if that’s an inappropriate derailment.
I’m not discounting anything. I’m just saying that statements like this:
Are not factual statements.
“Australopithecus”, being a genus, covers quite a few species, some with differing degrees of sexual dimorphism and some we know basically nothing about in terms of dimorphism. I remember there being a debate early on wrt A. afarensis whether there was a tremendous degree of sexual dimorphism, or if the researchers were actually looking at two different species. (Not sure if the debate is fully over, but the “single species” hypothesis seems to be the consensus now.)
I think these guys are so eager to be able to infer behavioral aspect of our ancestors that they stretch the ability of their sample size to actually make those inferences. And, of course, we get very sloppy science reporting that take things out of context and turn them into a headline just to grab people’s attention.
That argument doesn’t parse. Somehow it reminds me of the person who said Jesus of Nazareth was taken to Golgotha to be executed, Golgotha being a word meaning “the place of the skull”, it having been given that name because Jesus was taken there to be executed.
I don’t get your argument.
In species with lots of male-male competition over mating there tends to be higher sexual dimorphism. Or to put it another way, males evolve larger size, intimidation signals, and dueling weapons when they have to compete with each other.
A think Ahunter was wondering which way you believed the arrow of causality was running. It seems to me that there’s some co-evolution of traits here. Male-male competition means selection of traits that improve success in competition, and then competitive males crowd out other males, leading to increased value in competition-improving traits. And the extreme examples are ornate structures like antlers in deer or peacock tails.
But animals often have a lot of behavioral plasticity, and so we find closely related species that have very different reproductive strategies, which means that a species can get bumped into a new breeding strategy fairly easily. Just look at hominoids–we have pair-living gibbons, solitary orangutans, single-male multi-female harems in gorillas, multi-male multi-female groups in chimps, and multi-male multi-female groups with semi-permanent pairing in humans. In all species except gibbon species the males are substantially larger than females.