Is personality inherited, or is it shaped by our environment? This long-standing debate about nature versus nurture continues to intrigue scientists and philosophers alike. While research suggests that 30% to 60% of personality traits are inheritable, the precise extent and mechanisms remain a mystery. Here's what we know so far.

Genetic Roots Of Personality

Personality traits are patterns of thoughts, feelings, and behaviours that distinguish one individual from another. Studies comparing identical twins—who share 100% of their DNA—offer compelling evidence of genetics playing a significant role. Even when raised apart, twins often display similar personality traits, more so than non-twin siblings or adopted children.

Research Focusses On Big Fives Of Personality

These studies largely focus on the "Big Five" personality traits: neuroticism, extraversion, openness to experience, agreeableness, and conscientiousness. Research has identified 42 genetic variations across 727 DNA regions strongly linked to personality traits. For instance, gene variants like DRD2 and DRD4 are associated with novelty-seeking behavior, while others, like MAOA, are linked to introversion in specific contexts.

However, much of the human genome remains unexplored. While some traits, such as extraversion and conscientiousness, show high heritability, others, like openness to experience, appear less genetically influenced.

Role Of Environment in Personality Development

Environmental factors significantly shape personality. Early childhood experiences, cultural influences, and even socioeconomic conditions can activate or suppress genetic tendencies. For example, children raised in adverse environments, such as those involving neglect or abuse, may exhibit higher impulsivity due to the activation of certain temperament genes. Conversely, nurturing and stable environments promote calmer temperaments.

This interplay between genes and environment underscores the complexity of personality development. Even traits rooted in genetics can be modified through experiences and external influences.

Personality Across the Lifespan

Personality isn't fixed. It evolves, particularly during early adulthood. While personality traits have their roots in temperament—a concept observable as early as 4 months old—they remain fluid throughout life. Temperament includes reactivity (emotional responses) and self-regulation (control over these responses).

A 2020 study notes that significant personality changes occur between ages 20 and 40, a period often marked by life-altering experiences like higher education, careers, and relationships. However, even in later years, personality can adapt in response to new challenges or circumstances.

What Traits Are Heritable?

The National Library of Medicine links specific gene variants to certain temperamental traits. For instance:

- DRD2 and DRD4: Novelty-seeking

- KATNAL2: Discipline and caution

- PCDH15 and WSCD2: Sociability

- AGBL2 and others: Anxiety and depression

Still, heritability varies. A 2015 study estimated openness to experience and neuroticism to have around 15% heritability. In contrast, traits like self-directedness and cooperativeness were found to be 50%-58% heritable.

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While genetics lays the foundation for personality, environmental factors and life experiences shape its expression. As science advances, the intricate dance between nature and nurture continues to unfold, offering deeper insights into what makes each of us unique.

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India has reported its second human fatality due to highly pathogenic avian influenza (HPAI) or bird flu, marking the first such death in four years. While bird flu infections in humans are rare, they are highly lethal, with a fatality rate of one in two cases. The most recent victim was a two-year-old girl from Palnadu, Andhra Pradesh, who passed away in mid-March after being hospitalized for over 10 days at the All India Institute of Medical Sciences (AIIMS), Mangalgiri.

The pathogen responsible for the infection and subsequent deaths was confirmed only on 31 March, following a survey by the Indian Council of Medical Research-National Institute of Virology (ICMR-NIV). According to details shared by the state government, the child, who had a habit of consuming raw chicken, was admitted to the hospital on 4 March with symptoms including fever, breathlessness, nasal discharge, seizures, diarrhea, and reduced feeding. Two days before falling ill, she had reportedly consumed raw chicken. She succumbed to the infection 12 days later.

In a statement issued on Wednesday, the state government noted that no abnormal cases of respiratory infections had been identified in the ongoing survey. However, surveillance will continue for the next two weeks, with testing arranged for any suspected cases. Union health ministry officials stated that, based on data from the Integrated Disease Surveillance Programme (IDSP), no unusual surge in influenza-like illness (ILI) or severe acute respiratory illness (SARI) cases has been observed in the district in recent weeks.

A national joint outbreak response (NJOR) team has been deployed to conduct an epidemiological investigation and provide assistance to the state.

3 States Impacted By Bird Flu

This year, outbreaks of HPAI—also known as Influenza A virus subtype H5N1 or bird flu—have been reported in Maharashtra, Karnataka, and Andhra Pradesh. The trend follows a similar pattern observed in 2024, when states such as Jharkhand and Kerala, along with the aforementioned three states, recorded widespread H5N1 infections in poultry, prompting authorities to cull thousands of birds.

The Union government emphasized that "human-to-human transmission of the H5N1 virus is uncommon, and the risk of any other epidemiologically linked case being reported is assessed to be low."

India's first recorded human infection of the H5N1 influenza virus occurred in 2021 when an 18-year-old boy in Haryana succumbed to the infection within days of contracting it.

In May last year, Australia reported its first human infection with H5N1, stating that the patient had acquired the virus in India. Towards the end of 2024, the deaths of four big cats—three tigers and a leopard—were attributed to H5N1 infection.

Oxytocin, commonly referred to as the "love hormone" because it is involved in bonding and social behavior, is now being investigated for its surprise effect on pregnancy. Although oxytocin is traditionally linked to childbirth, milk letdown during lactation, and emotional bonding, recent findings indicate that this hormone can possibly delay early pregnancy. A study on mice conducted recently has helped explain how the hormone can stop embryonic growth, which may provide new understanding of human fertility and pregnancy.

In a few mammals, such as marsupials, bats, and more than 130 others, a process called "diapause" takes place. This is a natural biological phenomenon that sees embryos suspend their development in order to wait until the right conditions prevail for pregnancy to resume. Although very uncommon and hard to monitor in human beings, clinical experience from in vitro fertilization clinics indicates that human embryos might at times show delayed implantation. One highly documented case in 1996 showed that an embryo implanted in a uterus was in a suspended state for five weeks before implantation took place.

The new research by scientists at the NYU Grossman School of Medicine investigated oxytocin's possible role in inducing this pause in pregnancy. Their results indicate that oxytocin could be a major player in controlling diapause in mice, and they raise questions about its possible role in human pregnancies.

Oxytocin-Induced Pregnancy Pause

To study the impact of oxytocin on pregnancy, scientists tested female mice who had recently given birth by letting them be mated while still lactating. The research revealed that nursing females had pregnancies that lasted about a week longer than those of the non-nursing mice. Since the normal pregnancy in mice takes only 19 to 21 days, this postponement is a drastic halt to embryonic development.

The research team then sought to determine how this pause occurred. Using optogenetics, a technique that enables the activation of specific neurons through light stimulation, they artificially triggered the release of oxytocin in pregnant mice. After five days of oxytocin stimulation, the researchers examined the mice’s uteruses and found that five out of six had embryos in a dormant state, indicative of diapause. Conversely, pregnant mice that were not administered oxytocin stimulation did not exhibit any indication of developmental arrest.

In further confirmation of their research findings, the scientists administered oxytocin to early-stage mouse embryos in the laboratory setting. They detected identical cellular alteration related to diapause, implying that oxytocin has a direct influence on suspended embryonic development.

How Oxytocin Affects Embryonic Development?

The research showed that oxytocin slows down the process through which embryonic cells convert genetic information into proteins. This process, essential for growth and development of the cell, is copying DNA instructions into RNA, which then guides protein synthesis. By suppressing this process, oxytocin puts the embryo into suspended animation.

Interestingly, scientists also learned that embryos without oxytocin receptors were still able to enter diapause, suggesting that more than one biological pathway is used to trigger the pause. Still, having working oxytocin receptors seemed to increase the embryo's chances of surviving the halted state. When oxytocin receptors in the embryos were deactivated, survival rates while in diapause fell to 11% from 42%.

Implications for Human Fertility and Pregnancy

Although this research is in its infancy, it presents exciting possibilities for human fertility studies. A better grasp of the role oxytocin plays during early pregnancy may lead to significant advances in treating unexplained infertility and recurrent miscarriage. If human embryos can enter a state of diapause, further study could reveal how hormonal or environmental influences are responsible for early pregnancy loss.

Also, these discoveries may have greater implications outside pregnancy. As oxytocin is implicated in cell survival, researchers now want to know if what it does in diapause can help understand how to keep nerve cells from dying in the developing nervous system. What stops cells from dying early on might help neurobiology and regenerative medicine advance.

Even with these thrilling findings, much remains to be answered. How long can diapause be in various species, including humans? What are other biochemical signals that cooperate with oxytocin to control embryonic development? And might this information one day lead to targeted fertility treatments or interventions?

More studies are needed to uncover these secrets. As researchers learn more about the multifaceted functions of oxytocin, its image as just the "love hormone" is changing. This potent molecule seems to play a much more intricate function in reproductive biology than has been known, and it may play a role not only in when life starts, but in when it temporarily gets suspended.

Oxytocin's role in pregnancy is turning out to be more complex than originally thought. Though still a primary force behind labor and maternal attachment, it has also recently been found to retard embryonic development, which could have far-reaching consequences for reproductive science. As more research unfolds, the hormone could provide new insights into fertility, enhance IVF success, and even prevent early miscarriage. The possibility of oxytocin-based fertility therapies is an exciting one, and future research will be important to determine how this information can be translated to human pregnancy.

A study published in the New England Journal of Medicine has listed five key factors that impact the longevity of individuals. The research tracked participants for up to 47 years, assessing how five specific factors influenced their risk of death, longevity, and the number of healthy years they could gain by altering these habits. The conclusions of this study were based on data analyzed from over two million adults aged 18 and above across 39 countries.

Five Factors That Influence Longevity

• High blood pressure
• High cholesterol
• Diabetes
• Smoking
• Bodyweight, including being overweight and underweight

Women Could Add 14 Years To Their Lives

As per the researchers, women who didn't have these five risk factors at age 50 could potentially add more than 14 years to their lives, and men could gain almost 12 additional years. Men were most affected by these factors as those with all five faced a 94% chance of dying before 90, while their counterparts without these issues had just a 68% chance. Women with all five risk factors at age 50 had an 88% chance of dying before 90, whereas those without these problems had a 53% chance.

Diabetes Is The Main Factor

Out of all the factors, cholesterol was the least impactful of all. As per the study, people who lowered their cholesterol levels could only add 1.2 extra healthy years to their lifespan. On the contrary, individuals who quit smoking could potentially extend their lives by up to six years. Women who do not have diabetes could gain an extra 6.4 years, while men without the condition might see an increase of 5.8 years. Even a slight reduction in blood pressure could lead to an additional 1.8 healthy years, and achieving a normal BMI could contribute an extra 2.6 years, with variations depending on the region.

Importance Of Lifestyle Changes

The study reinforces the importance of lifestyle modifications in extending a healthy lifespan. The researchers noted that small but consistent changes in daily habits could significantly impact longevity. For example, maintaining an optimal weight through a balanced diet and regular physical activity helps control blood pressure, diabetes, and cholesterol levels, reducing overall health risks.

Smoking cessation emerged as the most crucial lifestyle change that could dramatically influence lifespan. Quitting smoking, even later in life, significantly reduces the risk of cardiovascular diseases, lung disorders, and certain cancers, contributing to longer and healthier lives. Similarly, diabetes management through dietary changes, regular exercise, and proper medical intervention plays a vital role in preventing complications and enhancing longevity.

Regional And Gender-Based Differences

The study also highlighted variations in longevity gains based on gender and geographical regions. For instance, men were more susceptible to the adverse effects of these five risk factors than women. This disparity could be attributed to lifestyle differences, genetic predisposition, or healthcare access.

Additionally, in certain countries with high obesity rates, maintaining a normal BMI was one of the most significant contributors to longevity. Meanwhile, in regions with lower tobacco consumption, factors like high blood pressure and diabetes had a more prominent role in affecting lifespan.