Yes, there seems to be a direct connection between our Jameson family and that of at least one particular Thompson family. The connection was discovered when the YDNA tests from our Jameson family were found to be exact, or nearly exact matches with several separate, although probably closely connected, Thompson families.[1] It can therefore be assumed that those persons tested with identical YDNA results and their associated known common ancestors and descendants covered by these results are in fact directly related.

The Jameson family with these YDNA results can be proven (as to this YDNA) as far back as Hugh Jameson in the very early 1700's, prior to his emigration to America.[2] The tested Thompson families are (so far) only proven as far back as the middle 1800's.

Although there can be no question that both families are descended from a common ancestor, that exact ancestor (the who, what and when) is not really known. Several explanations are possible.

The most likely explaination for this connection is that the descendants of our Jameson family and the identical (YDNA) Thompson families (who are quite probably at one time all of the same Thompson family), descended from a common ancestor, most likely in Scotland, and from a time before surnames were used, as we know them today. The name Jameson is widely believed to be used for that of a son of James, along with a given name, to distinguish among his siblings. Thomson, or Thompson[3] may have been used similarly for those children born to a son Thomas. Both James and Thomas may have been the sons of that common ancestor.

It is also possible the families came together when a child of one family was born into or adopted by the family of the other and the descendants of that child have assumed the surname of the other from that point on. A common example could be where the widow of one family remarried to a male of the other and the widow and all the children of the first marriage assumed the surname of the second husband. The descendants of this family would then have the YDNA from the first husband and the surname of the second, on down is successive generations, forever. Or similar confusion in cases of unwed birth, divorce, abandonment or other estrangements where the child takes the surname of the mother, yet has the YDNA of the unknown or unrecorded father.[4]

It is also possible that for reasons unknown, a different surname may have been taken by any male and/or family and the descendants known by that surname for all successive generations. O'Laughlin specifically says this about the Thompson family in his book; "Several other families now using the name of Thompson etc., in Ireland were originally of another surname entirely. Mc Tavish and Mc Avish are two such instances. People of these names have changed their names into Thompson on occasion, as documented by the Registrar-General in relatively recent times."[5]

Thompson and Jameson families were known to be in Ulster, Ireland during the 1600 and early 1700's and indeed to this day. The Ulster Irish Thompsons of the 1600's suggest Scottish Thompsons as much as Ulster Irish Jamesons of that same period suggest Scottish Jamesons. In fact the family name Thompson ranks among the top 50 names in Ireland, Scotland, and England. It is actually the 4th most common in Scotland and the 15th most common surname in England. Thus, those of the name in Ireland often have Scottish or English backgrounds.[6]

Although, in the case of our Jameson family, the genealogical records and other data are pretty solid all the way back to the immigrant Hugh Jameson in the very early 1700's and YDNA testing of descendants now proves these connections. The same cannot be said for the wider Jameson family of which he was only a part. Furthermore, we don't really know about the Thompson family to which we are an exact YDNA match. At this point we understand they can trace their ancestors back to about the mid 1800's and do not yet have an understanding how they themselves are related, let alone their ancestry or greater family. It is possible as we all learn more about our respective families our interrelationship will be better understood. It is also possible, given the fog of history, that apart from the YDNA match, we may never know.