Why so many different results ?

Introduction

This page is the fourth part of a study of articles.

Blood type and personality by Mary Rogers and A. Ian Glendon

A Pilot Study Using AI for Psychology: ABO Blood Type and Personality Traits by Masayuki Kanazawa

Is it true or not ?

As many experiments have been done and many papers have been published, the design and methods of these are definitively important.

However, it is possible that another factor greatly influences this field and the broader field of personality psychology.

That problem is the researchers themselves.

As in the two articles presented, the thought of the researcher fits the final result.

in the first article, the writer seemed to be pretty suspicious of the relation and found results not supporting the relation.

In the second article, the author seemed to believe in it and found supporting results. He also had done other studies with supporting evidence.

This isn’t necessarily a case of untruthful manipulations such as p-hacking, although it may.

Simply, a researcher who believes in something will look for evidence for it. This makes them more likely to find evidence or data that matches their beliefs.

It would be possible to find groups of people chosen randomly to have significant differences in personality or anything, if it is searched well.

Part 1 : The root of the Blood type – personality relation

Part 2 : Evidence supporting the blood type-personality relation. Are they legit ?

Part 3 :