The Mismeasure of Man by Stephen Jay Gould

(nextflipdebug2) #1
LL LW TL TW

LL 1. 0

LW 0.80 1. 0

TL 0.60 0.48 1. 0

TW 0.30 0.24 0.1 8 1. 0

Tetrad difference:

0.60 x 0.24 -0.48x0.30

0.144-0.144 = 0

no group factors

LL LW TL TW

LL 1. 0

Tetrad difference:

LW 0.80 1.0 0.40 x 0.40 - 0.20x0.20

0.16-0.04 = 0.1 2

TL 0.40 0.20 1.0 group factors for lengths

and widths

TW 0.20 0.40 0.50 1. 0

6 • 8 Tetrad differences of zero (above) and a positive value (below) from
hypothetical correlation matrices for four measurements: LL = leg length,
LW = leg width, TL = tail length, and TW = tail width. The positive
tetrad difference indicates the existence of group factors for lengths and
widths.

Free download pdf