Table 2 Trait heritability results
Sulcush2h2 SEh2 P-valuenSignificant covariatesAverage length VpVa
arsp*0.3540.081<0.001675Age2, CC15.95.9112.092
cs*0.2810.076<0.001621Sex, CC95.848.4972.388
iar0.0530.0720.178670Age, age-by-sex, age2, CC60.225.4181.347
ips*0.1330.0750.002491Age, age-by-sex, CC75.7212.9361.721
lf*0.2350.103<0.001429Sex, CC99.3418.5794.366
lu*0.1970.1210.01360Sex, CC75.7310.8362.135
ps*0.5120.113<0.001541Age, sex, age-by-sex, CC59.495.3852.757
sts*0.1140.090.036359Sex, age, age-by-sex, age2, CC115.8615.1841.731
Larsp_ yn0.56270.812
Lspcd _yn0.56630.905
Rarsp _yn*0.1290.0700.0037370.826
Rspcd_ yn*0.150.0197470.876
  • Heritability (h2) estimates, heritability standard errors (SE), and significance (P) calculated for each of the 10 metric sulcal length measures (boldface) and 6 nonmetric traits (roman). Significant results are indicated with asterisks by the trait name. Covariates that emerged as significant for that trait during screening and the trait sample size are listed. Age-by-sex is the interaction between age and sex; CC is cranial capacity. Sulcus average lengths are in millimeters. “Average length” reports for nonmetric traits are the frequency of occurrence of the presence of that trait for arsp and spcd phenotypes and the frequency of forked cs. Vp is the phenotypic variation for traits; Va is the additive genetic variation for traits.