Should States Repeal Their Laws Banning First Cousin Marriage? – Effects of first cousin marriage on health risks for their children

This minds-on discussion/worksheet activity challenges students to analyze which types of genetic conditions will be more common among children of first cousin marriage and to use evidence concerning the magnitude of observed health effects to evaluate whether laws banning first cousin marriage in 25 states should be repealed.  

The first attached file has the Student Handout and the second attached file has the Teacher Notes.


GeneticsCousinsSHO.doc38 KB
GeneticsCousinsTN.doc78 KB


Barbara H's picture

My parents were 1st cousins

I'm just discovering this web page and want to toss in my 2 cents worth.

My parents were indeed 1st cousins. They are both passed now but I know that back in 1949 they had a (Jewish) religious ceremony in Illinois but had to go to New York for a legal one.

I don't know if it was due to the fact that they were closely related (genetically) but they did lose two children, one within a few days of birth and another one after 3 months. At that point they chose adoption. Then two years later I was naturally conceived and born and at 59 I'm sill here. In my opinion, we love who we love...PERIOD! Obviously I thank G-d every day that they chose each other or I wouldn't be here today. I have two children of my own now which means they wouldn't be here either.

Some people may feel my parents had no right to marry, and they are entitled to their opinion. Remember though, if they are entitled to their opinions then so are the rest of us with the opposite opinion. Our lives are G-d given and he gave my mother to my father.

gotitbad's picture

fast forward genetic education

In this day and age only the ignorant would ban such unions.

iwaldron's picture

August 2012 revision

The revised Student Handout increases the focus on (1) student understanding of the genetics of increased health risks for the offspring of first cousin marriages and (2) using evidence to make decisions about social policy.

David Silvernail's picture

First Cousin Marriage/Dating

First cousin marriage/dating should be allowed without question. The risk is only 2% to 4% increase risk. Alcohol, drugs, smoking, and age is extremely more higher risk than two first cousins. So we should make it illegal for those who risk Alcohol, drugs, somking and age right? Put them in jail right? Never, that would be the majority of America. What about all the sperm donors and such? We don't know if the person next to us is our cousin. For the bible issue, regardless of how the people misinterpret Leviticus, God still encourage his main characters in the bible to marry there cousins. There are many of famous people who have, and have had children and where geniuses. Our President Roosevelt, Albert Einstein was a child of first cousins and his children, and many people to this day. How would you feel being banned from 25 states over peoples illiterate education ? I have served in the United States Military. You can marry/date your cousin in the District of Columbia but yet not in Indiana/24 other states? This is the United States of America, it should be legal without question across the USA. This country was based on cousin marriage. The bible, the Indians, Christopher Columbus all married there first cousins and cousins. Use your brains people!!! Albert Einstein did :)

Amanda's picture

First cousin marriage

Amen! I agree whole heartily. You can not help who you fall in love with. I can't stand the idea that someone could go to the very next state to get married but not their home state. Birth defects are much lower than previously thought to be. I don't believe that first cousins should have to gide their relationship because of fear of loosing their children to be tovether or worryi g about going to jail. I don't feel as though anything is wrong with being with your cousin. I wish otber people would get with the program and start repealing these laws.

Don Watson's picture

First Cousin Marriage

Absolutely NOT !!!! I believe First Cousin marriage laws should definitely stay in place in states that PROHIBIT this behavior... Scientific research has produced EVIDENCE that there is a higher risk of genetic diseases from this practice... ANY increased risk is too much....Also, people loved to TRY and use the Bible to justify marriage between First Cousins... This is also WRONG !!!! True in Leviticus chapter 18, it does list SPECIFIC relatives U should not marry and does not SPECIFICALLY mention first cousins there.. HOWEVER, the first verse of that particular text does say "None of U Shall Approach To Any That Is NEAR OF KIN"... Now that definition of "Near Of Kin" is also referenced AGAIN in Leviticus Chapter 25, Verse 49.." Either His Uncle OR His UNCLE'S SON or any that is nigh of kin unto him of his family may redeem him, or if he be able he may redeem himself... This verse gives specific authority to First Cousins and makes a distinction between First Cousins and more distant cousins... And also just because something was practiced in Biblical times, does not make it wise for today's society... FIRST COUSIN MARRIAGE SHOULD REMAIN OUTLAWED in the states where it is already... And should be outlawed in others.....

gotitgood's picture


Your ignorance astounds me.
Albert Einstein's parents were first cousins and he married his first cousin.
Charles Darwin (who knew a little about genetics lol) married his first cousin.
The US is the only western country do do so and this was primarily because of lack of genetic understanding, the invention of the automobile and to force wealth and power distribution from families.
Each of us has millions of distant cousins. My belief is that most Americans are tenth cousins (or closer) to every other American. Some geneticists believe that everybody on Earth is at least 50th cousin to everybody else.
Interesting read linkChances are that you and your spouse were already related before your marriage.

Post new comment

The content of this field is kept private and will not be shown publicly.