A disanalogy with RCTs and its implications for second-generation causal knowledge.

Area of Science:

• Genetics
• Causal Inference

Background:

• Family-based genome-wide association studies (GWASs) are proposed as a method to gain causal knowledge.
• Previous research suggests GWASs can identify genetic associations.

Purpose of the Study:

• To evaluate the potential of family-based GWASs in generating second-generation causal knowledge.
• To compare the utility of GWASs with randomized controlled trials (RCTs) for causal inference.

Main Methods:

• Comparative analysis of family-based GWASs and RCTs.
• Examination of the nature of causal stimuli assessed in both study designs.

Main Results:

• Family-based GWASs involve highly heterogeneous causal stimuli.
• RCTs typically involve homogenous causal stimuli (treatments).
• The heterogeneity in GWAS stimuli limits direct translation to causal knowledge.

Conclusions:

• Optimism regarding family-based GWASs for causal knowledge is tempered.
• Significant differences between GWASs and RCTs hinder the direct generation of second-generation causal knowledge from GWAS findings.