It used to be believed that you were teaching a baby to cry more if you picked them up when they cried, thinking that that baby will learn to cry to get attention. The opposite has been proven to be true. When you pick up a crying child, you are helping them to regulate (co-regulation) and they will, as a result, be more resilient, especially when this attention is given in the first year.
When a toddler, ages 1.5, 2, 3 (or sometimes older too), has a meltdown and is crying, it is often related to autonomy and security. Their idea of independence and having a lack of physical ability to accomplish what they are imagining themselves doing. They need your positive attention, picking them up, responding with love and patience, please don't feel threatened. It's not about you.
Dr. Jean-Victor Wittenberg,(child psychiatrist and Head of the Infant Psychiatry Program at the Hospital for Sick Children in Toronto and Co-Chair of Infant Mental Health Promotion (IMHP) which provides teaching for front-line professionals and develops advocacy initiatives on behalf of infant mental health), recently stated that you don't need to squelch that behavior. When they are having a meltdown, It's about them and their development and personal frustration and insecurities. By helping them regulate, offering help and concern, hugs and attention, it helps them know that this world is a good place and you are not going anywhere. You child may be realizing there are relationships outside of yours and theirs and they are insecure about it. You need to fortify that bond for them.
It's understandable that you want to teach good behavior but it's the underlying regulation issues going on under the tantrum that need addressing which will bring about better long term behavior with resilience and independence.
Learning Self Regulation is a long, ongoing process and in the learning period, there is a lot of co-regulation that goes on between caregiver and child to help the child learn to control his/her emotions and modify them, or in other words, to deal with the big emotions that come with the ups and downs of life.
This is why I like gentle methods when it comes to sleep. The temperaments of babies vary and we as caregivers need to modify our responsive to give them the best chance of good mental health and life success.
Tracy Spackman is a Certified Gentle Sleep Coach