Exploring the relationship between science and love this Valentine’s Day

A scientific perspective on love

Valentine’s day symbolises love, but what does it mean to be in love? The classic British sci-fi show Red Dwarf described love as, ‘A short-term hormonal distraction’. Ask a scientist about love and they will explain the physiological reasons for this ‘hormonal distraction’.

Many things happen in the body and brain when you fall in love. Flushed cheeks, a racing heartbeat and clammy hands are some of the outward signs of being in love. But inside the body there are definite chemical changes occurring. Meeting that special someone with attractive pheromones triggers a roller-coaster ride of emotions propelled by a gamut of hormones. It all starts with a tiny gland situated just behind the nose. The hypothalamus registers your interest in the new object of your affection and directs your pituitary gland to kick off chemical chaos within your body, starting with a boost to testosterone levels.

Both men and women produce testosterone, though men produce more. It can also be exchanged in saliva while kissing. Adrenal glands release adrenaline, which gets the heart rate up and also explains those clammy hands and flushed cheeks. Dopamine, a neurotransmitter involved in reward and pleasure, gives you that warm, fuzzy feeling. Phenylethylamine makes us feel a little high, similar to being on amphetamines. Norepinephrine works in a similar way to adrenalin, giving us the energy needed to get by on much less sleep than usual.

The final kicker in this chemical cocktail comes from oxytocin, nicknamed ‘the love hormone’. Released during intimacy, oxytocin lowers heart rate and stress levels. It helps us feel more bonded to our partners. Sadly, our bodies can’t keep producing hormones at such a crazy rate, so the giddy ‘in love’ phase can’t last. Eventually, it gives way to the ‘long-term attachment’ phase, governed by oxytocin and vasopressin, another bonding chemical. This explains how those in a new relationship might celebrate Valentine’s Day with wild romantic gestures, and many years later be completely happy with a night watching TV wearing flannelette pyjamas.

Happy Valentine’s Day from the IntoScience team!