Baby development Baby Understanding your baby's emotions Behaviour expert Desmond Morris talks us through your baby's emotional development 1 of Ad break MoodsWhat influences a baby's mood so that one minute she's gurgling happily, the next she's fractious and miserable? Studies of babies reveal they are happiest with gentle stimulation. They become bored and restless if there's no activity of any kind and anxious if they are surrounded by intense activity. But what kind of gentle activity should this be? MoodsWell, a baby's mood can be affected by something as simple as the sound of a mother's heartbeat. Before she's born, a baby is exposed to certain sounds and movements that she later associates with peace and security, such as the rhythmic beat of her mother's body as she walks. These two sensations become deeply embedded in the developing brain of the feotus, and come to spell safety and protection, even after birth. So when a mother holds her baby close to her chest, the sound of her heart helps calm her baby. HumourHaving a sense of humour is fundamental to human behaviour - and it has benefits, too! Tests have shown laughter lowers blood pressure, boosts the immune system and reduces stress hormones. Laughter starts some time in the fourth or fifth month. Actions most likely to get a laugh include include a 'boo!' sound made by a smiling parent, or a raspberry noise as you blow gently against your baby's tummy. Being bounced up and down on a parent's lap, or lifted high in the air and gently swung from side to side are also appealing to your little one. FearsMost babies' fears stem from feeling a lack of protection, making him panic and start crying, as he tries to sound the alarm. Fear of fallingA baby panics at sudden changes in position or jerky movements, which he reads as signs that an upset mother senses danger, while being held gently and peacefully, makes him feel safe and helps him relax. Continue slideshow > Fear Fear of strangersUp to the age of about 6 months, a baby can't distinguish between close relatives and strangers and is quite happy for either to pick him up. From 6 months, however, he starts to recognise his nearest and dearest and may panic and start crying if a stranger picks him up. Eventually, your baby will learn that even other people can be friendly, but this takes time and cannot be hurried. FearFear of the darkIf a baby cries when left alone in his cot and the light in his bedroom is turned out, the chances are he isn't frightened of the dark, but if being separated from his parents. It's not until a child is about 2 years old that his imagination starts to create lurking monsters at the foot of his bed in his darkened bedroom. This is a natural phase most small children go through. PersonalityBabies have a distinct personality from a very early age. While one baby might be quiet, another - even if he has the same loving parents - may be alert, active or cry more often. So what causes the differences? Although we know very little about how genes influence personality, it seems certain that environmental differences cannot explain all the variations in character that we see in families. Although genes play a part, parents can still make a difference. It is possible to create a more balanced personality by encouraging a nervous child to feel more confident in extrovert activities and vice versa. Desmond Morris - BabyExtract from Baby by Desmond Morris£12.99, Octopus Books By Desmond Morris Comments Daily deals from top retailers Latest on MadeForMums Mamas & Papas issue urgent recall of multistage car seats Is 'papa' becoming the new 'dada'? These hipster parents reckon so The amazing story behind little Asher's first ever modelling job Kym Marsh: Why I think Cheryl's keeping mum on her 'pregnancy'