Table 1 Relationship between performance, brain neuroanatomical traits and population density.

From: Brain morphology predicts social intelligence in wild cleaner fish

Fitted model

N

Chi2

p-value

rank (i)

FDR-derived significance threshold

Pseudo-R2

95% CI

Effect size (Cohen’s d)

Upper

Lower

Performance ~ Forebrain size proportion * density

 Forebrain size proportion

18

0.563

0.453

20

0.0909

0.42

−5.29

2.39

0.05

 Density

0.030

0.862

27

0.1227

−1.43

6.99

0.12

 Forebrain size proportion × density

8.291

0.004

1

0.0045

23.69

1.36

0.86

Performance ~ Midbrain size proportion * density

 Midbrain size proportion

18

1.037

0.309

14

0.0636

−2.09

0.62

0.07

 Density

0.007

0.933

30

0.1364

−1.64

1.35

0

 Midbrain size proportion × density

0.646

0.422

19

0.0864

−0.84

2.53

0.06

Performance ~ Cerebellum size proportion * density

 Cerebellum size proportion

18

1.257

0.262

12

0.0545

0.41

0.07

12.62

0.43

 Density

0.002

0.968

31

0.1409

−0.42

10.69

0.28

 Cerebellum size proportion × density

7.194

0.007

2

0.0091

1.45

31.7

0.68

Performance ~ Brain stem proportion * density

 Brain stem size proportion

18

0.870

0.351

17

0.0773

−2.04

0.68

0.09

 Density

0.032

0.858

26

0.1182

−1.59

1.24

0

 Brain stem size proportion × density

0.001

0.976

32

0.1455

−1.26

1.29

0

Performance ~ Forebrain cell proportion * density

 Forebrain cell proportion

20

0.158

0.691

25

0.1136

−1.02

1.66

0.01

 Density

0.448

0.503

21

0.0955

−2.29

0.95

0.04

 Forebrain cell proportion × density

0.000

0.990

33

0.1500

−1.36

1.36

0

Performance ~ Forebrain cell density * density

 Forebrain cell density

18

0.008

0.930

29

0.1318

−1.83

0.86

0.02

 Density

0.008

0.927

28

0.1273

−1.38

1.59

0

 Forebrain cell density × density

1.173

0.279

13

0.0591

−0.54

2.21

0.11

Performance ~ Cerebellum cell proportion * density

 Cerebellum cell proportion

20

0.216

0.642

23

0.1045

−1.15

2.28

0.04

 Density

0.203

0.652

24

0.1091

−1.65

1.58

0.01

 Cerebellum cell proportion × density

2.179

0.140

6

0.0273

−2.85

0.32

0.19

Performance ~ Cerebellum cell density * density

 Cerebellum cell density

20

2.200

0.138

5

0.0227

0.43

−11.57

−0.63

0.43

 Density

0.414

0.520

22

0.1000

−0.61

5.39

0.23

 Cerebellum cell density × density

6.885

0.009

3

0.0136

35.47

1.8

0.62

Social competence ~ Forebrain size proportion * density

 Forebrain size proportion

18

6.118

0.013

4

0.0182

0.34

0.71

8.73

0.77

 Density

2.096

0.148

7

0.0318

−6.67

0.08

0.39

 Forebrain size proportion × density

1.517

0.218

10

0.0455

−1.26

7.04

0.2

Social competence ~ Cerebellum size proportion * density

 Cerebellum size proportion

18

0.976

0.323

15

0.0682

−2.11

0.69

0.06

 Density

0.790

0.374

18

0.0818

−2.59

0.58

0.13

 Cerebellum size proportion × density

1.874

0.171

8

0.0364

−4.63

0.4

0.16

Social competence ~ Cerebellum cell density * density

 Cerebellum cell density

20

1.512

0.219

11

0.0500

−0.97

1.86

0.03

 Density

1.569

0.210

9

0.0409

−2.55

0.31

0.22

 Cerebellum cell density × density

0.876

0.349

16

0.0727

−0.63

3.09

0.06

  1. All statistical tests were two-sided binomial tests.
  2. Values in bold indicate statistically significant outcomes. Significance threshold alpha was set at p ≤ 0.05. Due to multiple comparisons with a total of eleven models, values were then confirmed with a False Discovery Rate significance threshold adapted to each p-value.
  3. False Discovery Rate (FDR)-derived significance threshold was estimated with the following function: (i/m)Q, (with i: p-value rank; m: number of comparisons (here are 11 models); Q: maximum acceptable FDR set at 0.0567).
  4. Pseudo-R2 is a goodness-of-fit measure estimated as 1 − (residual deviance/null deviance).
  5. Cohen’s d interpretation: 0.2, small; 0.5, medium; ≥0.8 large effect.
  6. 95% CI 95% confidence interval.