I'm sure many of you are familiar with the traditional 'cousin calculator' chart, such the the one below (click to enlarge):
|Traditional Cousin Calculator Chart|
If you take a close look, you'll notice I've color-coded the chart how I think we normally perceive relationships. Essentially, our sibling and parents are one degree away, our nieces/nephews and 1st cousins are two degrees away, and so forth. A second cousin is generally perceived as one degree further away from us than a first cousin. A first cousin, once removed is, at least to me, in the same category as a second cousin, and that's what this chart shows.
Now how can we actually determine how closely we're related? One simple method is by how much DNA we share. If we add in the percentage of DNA present between any two relatives to the chart it looks a bit different (click to enlarge):
|DNA Cousin Calculator Chart|
I know one of my 5th cousins, and we share just 0.049% DNA. That's a half of a tenth of a percent. Not very much. Anyways, this was just an attempt to create some kind of objective view of family relationships. Of course, nothing having to do with family is really objective, right?