Kinship and Prosocial Behaviour Preregistration

Abstract

A reanalysis of data from DeBruine (2002) Facial Resemblance Enhances Trust, PRSLB.

Hypotheses

Hypothesis 1: self_pref

Cues of kinship will increase prosocial behaviour. Cues of kinship will be manipulated by morphed facial self-resemblance. Prosocial behaviour will be measured by responses in the trust game. The prediction is that the number of trusting AND/OR reciprocating moves will be greater to self morphs than to other morphs.

Criteria

  • t_lo is confirmed if analysis trust yields conf.int[1] > 0
  • t_hi is confirmed if analysis trust yields conf.int[2] > 0.2
  • r_lo is confirmed if analysis recip yields conf.int[1] > 0
  • r_hi is confirmed if analysis recip yields conf.int[2] > 0.2

Evaluation

Corroboration

The hypothesis is corroborated if the 97.5% CI lower bound is greater than 0 and the 97.5% CI upper bound is greater than 0.2 (the SESOI) for either the trust or reciprocation moves.

(t_lo & t_hi) | (r_lo & r_hi)
Falsification

The hypothesis is falsified if the 97.5% CI upper bound is smaller than 0.2 (the SESOI) for both trust and reciprocation.

!t_hi & !r_hi

All other patterns of results are inconclusive.

Analyses

Analysis 1: trust

t.test(kin$trust_self, kin$trust_other, paired = TRUE, conf.level = 0.975)

Analysis 2: recip

t.test(kin$recip_self, kin$recip_other, paired = TRUE, conf.level = 0.975)