By Roberta Estes, copyright 2011
One of the things that people who study the sciences in a university environment learn is how to think with both logic and reason. This training is necessary to form a hypothesis and to construct experiments that will truly address the question or questions they are attempting to answer, without bias. This technique is called Cause and Effect Cognitive Reasoning.
However, it's easy to get caught up with what is colloquially called "pretzel logic." And for those untrained as scientists, especially those who might want to believe something specific, it's very easy to see how pretzel logic occurs.
Let's look at cause and effect cognitive reasoning.
Example 1
1. Eighty percent of the cracks in blacktop streets occur when the temperature is over 90 degrees.
2. Deaths in the elderly population increase when the temperature is over 90 degrees.
Conclusion:
Cracks in the street are causing an increase in deaths of elderly people. Equally wrong conclusion - deceased elderly people are causing cracks in the street.
Why are these conclusions wrong? Because while items 1 and 2 are linked by the same underlying cause, neither of them is the cause of the other. It is incorrect to infer that they are.
Example 2
1. All canine animals are ferocious (for this example).
2. Bears are ferocious.
Conclusion:
Bears are canine animals.
Why is this wrong? Just because items one and two are individually accurate does not mean that you can draw any parallel, analogy or conclusions between items one and two.
This becomes more difficult when we introduce factors where we know the outcome to be true.
Example 3
1. All living things need water.
2. Roses need water.
Conclusion:
Roses are living things.
While this is factually true, it is not true because of the facts stated, but because of two facts that are not stated.
3. Dead things do not need water, and...
4. All thing are either dead or alive.
When these two extra data points are added, we can then correctly deduce the answer that roses are living things. However, to do so by using only statements 1 and 2 would be a logically incorrect process for the same reasons that our first two examples were wrong. It's difficult to understand this though, because we already know that all matter is alive or dead and dead things don't need water.
This is an example of letting pre-existing knowledge influence a conclusion. Even though people claim to understand this logic process when stepped through examples individually, and the methods for accurate deductive reasoning, more than 80% of the population still fails simple logic tests.
So now that we understand how NOT to get caught up in logic traps, let's move on to areas more relevant to genealogy.
Example 4
1. A DNA participant matches an individual whose ancestor is known to live a few kilometers from the participants ancestor in Germany.
2. The matches ancestor is Jewish.
Conclusion:
The participant is Jewish.
What is wrong with this conclusion? This is the same situation as Example 2 where the two individual statements are true, but no connection can be drawn between the two facts.
Could this be true, meaning could the participant's ancestor be Jewish? Yes, but one cannot state that it is true through logic or deductive reasoning based on only the information presented here. More information is needed.
What might the scenarios be?
The two individuals may have a common ancestor in the Middle East before the dawn of the Jewish religion and migrated to Germany independently.
The two individuals may share a common ancestor in Europe, and one family may have subsequently converted to Judaism.
The two individuals may share a common ancestor in Europe, and one family may have subsequently converted from Judaism.
The two individuals may share a common ancestor in Europe, and one family may have subsequently converted from Judaism.
There is not enough information given in items 1 and 2 to reach any conclusion about Jewish heritage for the participant. To conclude otherwise would be incorrect at best, and potentially unethical, depending on the circumstances and motivation for drawing the incorrect conclusion.
Example 5
1. A Y-line DNA participant claims to have Native heritage.
2. The DNA participant carries yline haplogroup R1b or a subclade.
Conclusion:
Haplogroup R1b indicates Native heritage.
This is the perfect example of pretzel logic. This is incorrect because while these items individually may be perfectly accurate, there is no logical link between the two. Here's why.
The individual may not have Native heritage at all.
The individual may have Native heritage, but not on the paternal line.
If the individual does have proven Native Heritage on the paternal line by genealogically accepted documentation sources, such as the Guion-Miller Rolls, the paternal ancestral DNA can still be European because many European males fathered children with Native women and those children were considered full tribal members due to their mother's tribal status. However, the DNA of these fathers is still of European origin, regardless of whether the children were considered tribal members or not.
No DNA tests on pre-contact burials produce any evidence of European haplogroups, so there is no reason to suspect that any haplogroup R1b members were part of either initial or later migrations to North America before European contact.
Example 6
1. A male in the Melungeon project carries haplogroup E.
2. An individual in the Portuguese project carries haplogroup E.
Conclusion:
Men who carry haplogroup E are Portuguese. Equally wrong conclusion - all Portuguese men with haplogroup E are Melungeon.
Why is this wrong? I'm sure by now you recognize the error in the logic. These two statements, while individually true, have nothing to do with each other. What might be more accurate situations?
There are many men in Portugal who carry haplogroup E. Haplogroup E was born in Africa and through migration and enslavement, haplogroup E subgroups are found throughout Europe and the Americas.
Melungeon males who carry haplogroup E need to be individually evaluated as to the locations of their matches, both current and ancestral, and results combined with genealogy.
Melungeons are defined as a particular group of individuals in a specific place and time, and people living in Portugal are not included in the group defined by documented records.
People who are members of haplogroup E can be found in nearly every geographic project, so finding one in the Portuguese project and logically connecting the Portuguese to the Melungeons due to this finding would come under the category of either pretzel logic or perhaps the desire for a particular outcome.
Searching for Data to Support a Desired Outcome
Drawing a conclusion and then attempting to fit data into the conclusion isn't science, it's deception, but unfortunately, to the uninitiated, it can sound quite compelling. This is why scientific review panels exist in the scientific world, to insure unbiased reporting of results and accuracy of logic in the scientific process. There are no internet police to regulate the truthfulness or accuracy of websites and what they have to say, but in academic publishing there are editors and peer review boards, and they are brutal. They do however, insure that the consuming public can have faith in the results within the limits of what science had to offer at the time of publication.
Summary
The internet is the perfect breeding ground for pretzel logic. People desperately want to believe one thing or another, someone is Native or isn't European, is Jewish or isn't, for example, and using pretzel logic, they can convince themselves, and sometimes others as well that A and B separately are true, so combine them to get C. This isn't a recipe, and A and B can't simply be combined.
At the following website, compliments of California State University at Fullerton, several examples of different types of faulty reasoning are provided. http://commfaculty.fullerton.edu/rgass/fallacy3211.htm
Dr. Robert Gass, who provides this website, specializes in Human Communications in the areas of persuasion, arguments, critical thinking and deception detection. http://commfaculty.fullerton.edu/rgass/
Don't fall into the pretzel logic trap. Be sure when you're evaluating logic statements and scenarios, especially those described by others that you don't allow previous knowledge, preconceived ideas or personal desires to cloud your vision. Be sure to ask yourself if these factors might be influencing the position of the individual making the statements.
