PDA Insiders

This is a simplified account of what Sally Cat called her "Big Traits Study" which suggests 105 traits that are distinct to PDA but not general autism.

Method

In 2016, Sally Cat invited fellow members of an online adult PDA group to suggest potential, distinct PDA traits for inclusion in an in-group poll. The 228 traits suggested were put into a Google Form poll, without editing any of the wordings. Members of the same adult PDA group were then invited to rank each of the 228 with 0 equalling "not at all" and 5 equalling "majorly". The results were filtered to select:

    All traits scoring an average of 3.5+ out of 5 

    A small number of very unusual traits (such as making up new names for people)

    Traits that were considered to be PDA indicators (being late learning to talk and being dyspraxic)

155 of the original 228 traits made it through the filter and were transferred to a second Google Form, which was completed by 290 people identify as PDA and 90 people who identified as being autistic but not PDA.

Results

In 2019, a Nottingham University Forensic Psychology PhD student, Grace Trundle, carried out a T-test analysis on the data, and found that, of 155 traits, 105 (over two thirds) showed a significant difference between PDA and “general” autism.

The results of Trundle's T test analysis are included below. For simplicity, Grace termed people who identified as autistic but not PDA as "ASD not PDA". 

According to Grace Trundle's analysis, PDA scored higher in every instance.