Thus far, all P-rr-tts tested have fallen within one of three different haplogroups (main branches of the human family tree). These particular 3 are called E1b1b1, I1f, & R1b1a2 (and its subbranches). The nomenclature was updated in 2011.

The DNA results indicate that most of the P-rr-tt families tested are not related to each other-- thus, the Parrott and related last names have come into use on several independent occassions.

The first three Parrott families listed above-- one from haplogroup R1b1a2, one from R1b1b2a1b and the other from I1f-- have enough DNA samples different individuals that they have been grouped by family. Collectively, these three families, along with the descendants of William Parrott of Talbot Co., Maryland, account for the vast majority of Parrotts in the USA.

The remaining P-rr-tt families are represented by only one or two DNA samples each, so they have been grouped according to their haplogroup (either E1b1b1 or R1b1a2.) Overall, there appear to be several unrelated P-rr-tt families in the US, Canada & England. Collectively, these additional P-rr-tt families in the US, though numerous, only account for a small percentage of the total.