Israel is missing from the list. May be it is the exception.

Doubtful. The most religious (who are poorer than the average Israeli) are the most fertile.

i agree with ben g's argument. but i think david box mentioned that this wasn't true actually. the haredi are after all a modest minority, so perhaps obscured by the trends in the secular + national religious? hopefully he'll chime in.

Does that include all surviving children?

The interesting thing about Israel is that it may be or may soon become like many third world countires where the typical correlation between SES and innate cognitive potential does not apply. Not because the natural cognitive sorting that modernization causes hasn't happened yet, as would be the case in many third-world countries, but because large numbers of highly fertile Ashkenazi (i.e. smart) Jews choose to live in poverty for religious reasons.

We tend to associate religion with stupidity (well, many of us do - just being honest here), but certain religious groups - most notably the Haredi and the Amish - are made up of relatively intelligent people, and actively negotiate their interactions with mainstream society in ways that seem to be conducive to long-term growth. In a couple hundred years, they may serve as islands of light in a gradually darknening cognitive landscape.

also, the arabs (who are poorer than the avg) are more fertile in israel.

maybe i'm wrong. i'd be interested in seeing what the overall means by SES are.

Ok, with the help of the Israeli Social Survey, I've calculated mean number of children for people by income group for all Israelis (Arabs, Jews, and others). Unfortunately, the website's options don't let you break it down by precise quintiles, but you get the idea.

Mean number of children for...

All income groups:..............3.017
up to 2500:....................... 3.346
2501 - 4000:......................3.229
4001 - 5000:..................... 3.18
5001 - 6500:..................... 3.269
6501 - 8000:..................... 2.96
8001 - 10000:................... 2.883
10,001 - 13,000:............... 2.761
13,001 - 17,000:............... 2.725
17,001 - 24,000:............... 2.648
24,000+ :......................... 2.981

So the general trend is consistent with what we see in other developed countries. Looking just at the "Jews and Others" category:

Mean number of children for...

All income groups:..............2.826
up to 2500:....................... 2.9
2501 - 4000:......................2.915
4001 - 5000:..................... 2.812
5001 - 6500:..................... 3.013
6501 - 8000:..................... 2.789
8001 - 10000:................... 2.722
10,001 - 13,000:............... 2.696
13,001 - 17,000:............... 2.693
17,001 - 24,000:............... 2.618
24,000+ :......................... 2.927

Interestingly, both the very poorest and richest Jews in Israel have slightly more children than average.

is it possible to break these statistics down by sex? I have the feeling that for women, lower SES = more children, decreasing with increasing SES, but for men, I wouldn't be surprised if the wealthiest fraction has a higher numbers of children because of the ability to get divorced, marry again, have more children with a younger woman, and possibly repeat the process again, never worrying too much about the costs of the children and repeated divorces.

This is anecdotal, but a lot of rich parents I've known would get divorced in their 40s and the father would usually remarry and father a half-sibling or two.

You could also try to find statistics about number of marriages by SES, broken down by sex. Who knows...

Be careful of using the label "developing country". For instance Armenia has probably demographics and history quite similar to some other "East European" countries (which definitely wouldn't call themselves a "developing country").