Sunday, May 31, 2009

NAMs and the Flynn effect: In the last post on the Flynn effect, I used GSS data to show that the mean Wordsum scores of people born in the United States of Mexican and Puerto Rican descent have risen over the past two decades. I list below the mean scores for a larger number of ethnic groups over the past four decades.

Mean Wordsum scores

Seventies 4.17
Eighties 4.04
Nineties 5.11
This decade 5.53*

Seventies 4.82
Eighties 4.91
Nineties 5.10
This decade 5.38*

1972-1989 3.68
1990-2008 4.47

Seventies 6.70
Eighties 6.74
Nineties 7.00
This decade 6.95

Seventies 6.14
Eighties 6.22
Nineties 6.28
This decade 6.40

Seventies 6.47
Eighties 6.30
Nineties 6.49
This decade 6.59

Seventies 6.11
Eighties 6.08
Nineties 6.43
This decade 6.47

Seventies 6.28
Eighties 6.43
Nineties 6.47
This decade 6.23

Seventies 7.08
Eighties 6.54
Nineties 6.77
This decade 7.03

Seventies 7.42
Eighties 7.58
Nineties 7.32
This decade 7.47

* Significant change between first and last period, .05 level, two-tail test.

The American Indian sample size is very low after you remove blacks and whites who say their main ethnicity is Native American, so I had to limit the comparison to two periods. The difference between the two would very likely be statistically significant if the sample were larger.

There is a clear pattern here: none of the white groups have seen significant improvements since the early 1970s when the vocabulary test was first given, but all of the non-white groups have improved. I suggested before that fewer NAMs have good English language models, but the increased hours of television viewing might have helped compensate in the last couple of decades. Kids watch several hours of TV each day, and they often watch peers that they want to imitate. Characters on television usually speak well. (Of course, it doesn't help if they are speaking another language well). White kids often have good models anyway, so people on television with good vocabularies are redundant.

Anyway, that is one explanation, but others ideas to account for the pattern are appreciated.

(TV can't be THAT powerful, or generations wouldn't continue to have strong accents.)


  1. Beastmaster9:34 AM

    Is this test available on the internet?

  2. I think it is probably due to improved nutrition during gestation and very early childhood - with some groups having reached a plateau of improvement earlier than others.


    Richard Lynn. What has caused the Flynn effect? Secular increases in the Development Quotients of infants

    Intelligence. Volume 37, Issue 1, January-February 2009, Pages 16-24


    Results of five studies show that during the second half of the twentieth century there were increases in the Development Quotients (DQs) of infants in the first two years of life. These gains were obtained for the Bayley Scales in the United States and Australia, and for the Griffiths Test in Britain. The average of 19 data points is a DQ gain of approximately 3.7 DQ points per decade. Similar gains of approximately 3.9 IQ points per decade have been present among preschool children aged 4–6 years. These gains are about the same as the IQ gains of school age students and adults on the Wechsler and Binet tests. This suggests that the same factor has been responsible for all these secular gains. This rules out improvements in education, greater test sophistication, etc. and most of the other factors that have been proposed to explain the Flynn effect. It is proposed that the most probable factor has been improvements in pre-natal and early post-natal nutrition.

  3. Before we start theorizing,

    SAT Verbal scores shows no improvement among Mexicans over the last 20 years:

    NAEP reading scores for Hispanics don't show this reliable pattern of improvement relative to whites either:

    So this is maybe just a change in the sort of people who are taking the survey? You'd know the methodology much better than I, but it looks more like Mexicans are just beginning to take their expected Wordsum position between white and blacks (although improved nutrition/education probably did boost black&Hispanic scores -on all tests- in the 70s).

  4. iPhone Ringtone Maker
    iPhone Ringtone Converter
    iPhone Ringtone Creator
    M4R Converter
    MP3 to M4R Converter
    M4A to M4R Converter
    AAC to M4R Converter
    Transfer iPhone SMS
    iPhone Ringtone Maker, a smart iPhone ringtone creating tool, can convert almost all mainstream videso/audio formats including AVI, MPEG, WMV, DivX, MP4, H.264/AVC, AVCHD, MKV, RM, MOV, XviD, 3GP, WMA, WAV, RA, M4A, MP3 to M4R iPhone ringtone, and transfer the converted M4R ringtone to iPhone directly without iTunes. Apart from converting common formats to iphone ringtone, the iPhone Ringtone Maker even supports converting music purchased from iTunes store to iPhone ringtone.

  5. Anonymous4:27 AM

    Ηello theгe I аm sο glаd I fоunԁ your
    site, I really found you bу mіѕtаkе,
    whіle І was searching on Digg for ѕomething еlѕe, Nоnethеlesѕ I
    am here noω and would juѕt like tо say many thanκs for а tгemendous post and a all
    гοund eхcіting blog (I
    also love the theme/desіgn), ӏ don't have time to go through it all at the moment but I have bookmarked it and also added your RSS feeds, so when I have time I will be back to read a lot more, Please do keep up the fantastic job.

    Also visit my site ... New Bingo Sites


Study of 94k Americans: Irreligious blacks do much more drug selling and theft than religious blacks

This study , using a sample of ~94k teens and young adults, examined the link between religiosity (church attendance and saying religion is ...