Twofold

Parenting

A New Take on Parent-Child Affinities

Nancy L. Segal Ph.D. on January 19, 2024

Who does your child resemble? You or your partner? Here's why it could matter.

Who does your child resemble? You or your partner? Here's why it could matter.

Understanding Twins

Twins Born in Different Countries: A Rare Occurrence

Nancy L. Segal Ph.D. on October 8, 2023

Twins born in different countries are very rare; only two such cases have been reported.

Twins born in different countries are very rare; only two such cases have been reported.

Understanding Twins

Twins' Memoirs and Autobiographies

Nancy L. Segal Ph.D. on August 24, 2023

What do twins' memoirs and autobiographies reveal about us? A lot.

What do twins' memoirs and autobiographies reveal about us? A lot.

Understanding Twins

Gay Dads, Twin Sons, and a Unique Citizenship Case

Nancy L. Segal Ph.D. on August 23, 2023

How a citizenship case for the twin son of a gay transnational male couple helped so many others.

How a citizenship case for the twin son of a gay transnational male couple helped so many others.

Sexual Orientation

A Gay Couple's Fight for Their Twin Son's Citizenship Inspires

Nancy L. Segal Ph.D. on July 13, 2023

The story of a gay couple that faced legal challenges from the U.S. when trying to obtain citizenship for one of their twin sons.

The story of a gay couple that faced legal challenges from the U.S. when trying to obtain citizenship for one of their twin sons.

Understanding Twins

The Twin Children of the Holocaust

Nancy L. Segal Ph.D. on May 5, 2023

Celebrating the twins who survived the Holocaust-and remembering the many who did not.

Celebrating the twins who survived the Holocaust-and remembering the many who did not.

Understanding Twins

What Do We Learn From the Twin Children of the Holocaust?

Nancy L. Segal Ph.D. on January 26, 2023

Read about a relatively unstudied and tragic episode in human history.

Read about a relatively unstudied and tragic episode in human history.

Understanding Twins

What to Know About Quadruplets: Origins and Experience

Nancy L. Segal Ph.D. on December 16, 2022

What is it like to raise quadruplets—and where do they come from?

What is it like to raise quadruplets—and where do they come from?

Understanding Twins

What Twins Tell Us About Artistic Skill

Nancy L. Segal Ph.D. on October 5, 2022

Where does artistic talent come from?

Where does artistic talent come from?

Imagine being raised in a different culture and hw that would affect who you are,

Understanding Twins

New and Noteworthy Twins

Nancy L. Segal Ph.D. on May 12, 2022

How often do you see twins in the media?

How often do you see twins in the media?

Understanding Twins

Identical Dilemmas: What Causes Identical Twinning?

Nancy L. Segal Ph.D. on February 9, 2022

Identical twins are popular in psychological science and in the media. Why have we still not figured out the biology behind them?

Identical twins are popular in psychological science and in the media. Why have we still not figured out the biology behind them?

Here are some excellent sources of information about twins.

Is there more to learn about the controversial 1960s study of twins? Yes.

Understanding Twins

Twins Separated at Birth: Growing Up Continents Apart

Nancy L. Segal Ph.D. on September 23, 2021

How would you feel if you met a twin you never knew about, who was raised in a different country?

How would you feel if you met a twin you never knew about, who was raised in a different country?

Understanding Twins

Reared-Apart Twins: Tales of Two Cities

Nancy L. Segal Ph.D. on September 15, 2021

How would you feel if you discovered that you were adopted and had a twin—but your parents denied it?

How would you feel if you discovered that you were adopted and had a twin—but your parents denied it?

Are you a twin who survived a twin pregnancy termination?

Are you, or do you know males who have fathered twins? If so, this article should be read!

Understanding Twins

Are There More Than Two Types of Twins?

Nancy L. Segal Ph.D. on December 26, 2020

Are you, or people you know, truly twins or truly twin-like?

Are you, or people you know, truly twins or truly twin-like?

Coronavirus Disease 2019

What Can Twin Studies of COVID-19 Tell Us?

Nancy L. Segal Ph.D. on October 14, 2020

Twin research around the world may help solve some COVID-19 dilemmas.

Twin research around the world may help solve some COVID-19 dilemmas.