Please don't check out on me simply because I used the word, "math" in the title of this post. What I want to do is to illustrate the complexity of stepfamilies mathematically. OK, just follow me here.
R = n(n-1)
R means the # of Relationships in a system from one person to another; n means the number of people in the system.
So, a family of 5 (Dad, mom, 3 kids) looks like this mathematically:
R = 5(5-1) >>>> R = 5(4) >>>> R = 20
Therefore, in a family of 5 there are 20 relationships.
Now let's enter the stepfamily of "5.” Let's say it is a couple with 3 kids. Biologically speaking, one is his, one is hers and one is theirs. Each of the adults has an ex-spouse (5+2=7), and each of these ex-spouses has remarried (7+2=9). Each of the ex-spouse's new spouses has 2 children from a previous marriage (9+4=13) and then they have a bio child in their current marriage (13+2=15). Let's just forget about (step) grandparents, (step) aunts, (step) uncles, and (step) cousins for the sake of simplicity.
Now, let's plug in our stepfamily web of relationships into the formula: R = n(n-1).
R = 15(15-1) >>>> R = 15(14) >>>> R = 210
So, in a bio family of 5, there are 20 relationships to manage, but in a stepfamily of 5 there could be 210 (or many more) relationships to manage.
To further make stepfamily life a challenge, the relationships are segmented and fragmented whereas in a bio family they are consolidated (assuming some level of health). So, this really adds a complexity multiplier to the mix. Allow me to illustrate. When Carly is at dad's house she has one relationship with dad, but when she is at mom's house she has a different relationship with dad. If she really likes dad, but really liking dad hurts mom's feelings, then she is likely to limit her positive talk of dad in order to save mom's feelings. Unless of course she is mad at mom, then she might increase positive dad talk. Either way, she has two relationships with dad depending on who she is with.
So, I will call this the "complexity multiplier" which multiplies the number of relationships by the level of complexity of those relationships. A "normal" bio family (please tell me if you've ever seen one) might have a 1.0 multiplier effect meaning their complexity remains at 20 (20 X 1 = 20). An unhealthy bio family (say dad is an alcoholic) might have a 2.7 multiplier effect making complexity rise from 20.0 to 54.0 (20 X 2.7 = 54)
Let's say that a "normal" stepfamily has a complexity multiplier of 2.0. Then suddenly that 210 relationships becomes 420.0 on the family complexity level. As you can see, the challenge is huge in a stepfamily.
Here is the good news: Accepting the reality that life is complex helps decrease the stress brought on by the family complexity. Resisting this complexity is not a fruitful exercise. Also, when a family finds a rhythm that is respectful to everyone, it reduces the complexity multiplier. And finally, having communication pathways that are safe for each member of the family can reduce the stress and complexity because then no one feels like they are trapped.