S1. Cohen’s kappa agreement coefficient. Agreement according to (Landis & Koch, 
1977). 

Variable  
Grade 

Threshold N Kappa  Agreement 

Shoveling UI1 3 109 
0.89 

Almost perfect 
agreement 

Double Shoveling UI1 2 109 
0.92 

Almost perfect 
agreement 

Interruption Groove UI2 1 102 0.70 Substantial agreement 
Tuberculum Dentale UI2 2 102 0.62 Substantial agreement 

Bushman UC 1 123 
0.83 

Almost perfect 
agreement 

Accessory cusps UP1 1 124 0.69 Substantial agreement 
Accessory ridges UP2 2 116 0.68 Substantial agreement 
Metaconule UM1 1 142 0.53 Moderate agreement 
Carabelli cusp UM1 3 142 0.61 Substantial agreement 
Hypocone UM2 3 127 0.64 Substantial agreement 
Parastyle UM3 2 81 0.63 Substantial agreement 
Lingual cusp number 
LP2 

2 129 
0.65 Substantial agreement 

Deflecting Wrinkle LM1 2 147 0.69 Substantial agreement 
Anterior Fovea LM1 2 147 0.54 Moderate agreement 
Protostylid LM1 2 147 0.56 Moderate agreement 
Entoconulid LM1 1 147 0.73 Substantial agreement 
Metaconulid LM1 1 147 0.63 Substantial agreement 
Groove Pattern LM2 Y 129 0.78 Substantial agreement 
Hypoconulid LM2 1 129 0.74 Substantial agreement 
Odontome UP/LP 1 500 0.77 Substantial agreement 

 
Landis, J., & Koch, G. (1977). The measurement of observer agreement for categorical data. Biometrics. 
  



S2.1. Spearman correlation test using data set A) only wear-biased traits. 

 

 

 

 

 

 

 



S2.2. Spearman correlation test using data set B) only unbiased traits. 

 

 

 

 

 

 

 

 

 



S2.3. Spearman correlation using data set C) with biased and unbiased traits