Table 1.

Phylogenetic signal in the cognitive data

Log likelihood
Data sourceDependent measureλ, ML*λ = MLλ = 0P
All speciesCylinder score0.83−2.14−4.130.05
A-not-B score0.72−12.60−14.900.03
Composite score0.76−2.00−3.470.09
PrimatesCylinder score0.95−0.62−3.630.01
A-not-B score0.48−6.05−7.540.08
Composite score0.86−0.98−3.320.03
  • * The maximum likelihood estimate for λ, a statistical measure of phylogenetic signal (201).

  • P values are based on a likelihood ratio test comparing the model with the maximum likelihood estimate of λ to a model where λ is fixed at 0 (the null alternative representing no phylogenetic signal).