The speaker begins by discussing the unique moral sentiments inherent to humans and his personal fascination with morality.

• Humans are distinguished by their fully developed moral sentiments.
• Morality is central to human social interaction, and the speaker has a personal obsession with understanding it.

The speaker's moral curiosity is credited to his upbringing as an altar boy and his mother's influence.

• Sister Mary Marastela, the speaker's mother, instilled in him a sense of morality.
• The speaker's religious upbringing provided time for contemplating the universality of moral principles.

The concept of a 'moral molecule' is introduced and the speaker shares his discovery of oxytocin.

• The speaker's quest to understand morality led to the hypothesis of a chemical basis for moral decision-making.
• After ten years of research, oxytocin was identified as the 'moral molecule'.

The speaker describes the properties and known functions of oxytocin prior to his research.

• Oxytocin is a simple molecule unique to mammals, involved in maternal behaviors and social tolerance in animals.
• In humans, it was recognized for its role in childbirth, breastfeeding, and sexual activity.

Initial skepticism about oxytocin's broader role led to experimental proof of its impact on trust and morality.

• Despite being dismissed as a 'female molecule', the speaker persisted in exploring oxytocin's effects on trustworthiness.
• Experimental challenges included the molecule's short half-life and the requirement for rapid collection and cooling of samples.

The speaker details his approach to quantifying moral behaviors, focusing on trustworthiness.

• The speaker chose to investigate trustworthiness due to its correlation with economic prosperity and alleviation of poverty.
• Instead of direct questioning, an economic game with monetary incentives was used to provide a measure of trustworthiness.

A trust game involving monetary transfers and blood tests was devised to study the relationship between oxytocin and trustworthiness.

• Participants decided whether to transfer funds to a stranger, knowing the amount would be tripled, and the recipient could then return a portion.
• The behavior in the game, combined with oxytocin measurements, revealed a positive correlation between received money, oxytocin levels, and returned funds.

The speaker explains the advancement from correlational to causal evidence by directly manipulating oxytocin levels in the brain.

• To establish causality, the speaker needed to directly increase brain oxytocin, which was achieved using nasal inhalers in experiments.
• Collaborative studies involving oxytocin inhalers confirmed its role in increasing trust and generosity without affecting mood or cognition.

Further investigation showed that oxytocin influences empathy, which plays a vital role in moral behavior.

• Experiments with emotionally evocative videos demonstrated that oxytocin levels predict feelings of empathy.
• Empathy enables connection with others, prompting help and moral actions.

The speaker references philosopher Adam Smith's work, aligning his findings on oxytocin with Smith's bottom-up theory of morality.

• Adam Smith's book 'The Theory of Moral Sentiments' posited that shared emotions underpin moral behavior.
• The speaker's research on oxytocin provides a biological basis for Smith's theory.

The speaker explores the dark side of oxytocin, revealing how its absence or inhibition can lead to immoral behavior.

• The speaker shares a personal anecdote illustrating how trust can be manipulated, connecting it to oxytocin function.
• Some people, including psychopaths, do not release oxytocin in response to trust cues, leading to immoral acts.

The interplay between oxytocin and testosterone is explained, highlighting testosterone's contrasting effects on moral behavior.

• Testosterone can inhibit oxytocin, leading to selfish behavior, but also motivates punishment of others' selfish acts.
• The balance between oxytocin and testosterone suggests an internal, biological mechanism for morality.

The speaker addresses the practical implications of his findings by examining situations outside the laboratory.

• Weddings and skydiving were used to study oxytocin release in real-world scenarios, showing its role in trust and connection.
• Social media and cultural universality of oxytocin's effects on bonding were also explored.

The speaker, dubbed 'Dr. Love', concludes with a message encouraging physical contact to boost oxytocin and enhance happiness.

• Physical contact, such as hugging, can increase oxytocin levels and improve relationships and happiness.
• The speaker humorously offers an alternative method of oxytocin administration for those averse to touch.