The ‘self-soothing’ argument is an outdated rationalization.
Research on brain development shows that babies don’t learn to self-soothe by being put down. They learn not to depend on others, because no one will come when they call. Babies learn to self-soothe by being comforted, which teaches them not to panic and to realize that their emotions are manageable. Being soothed when they cry actually changes the brain chemistry and neural connections so that babies learn to soothe themselves.
All babies benefit from a certain amount of time to play independently, and to watch you from a safe place as you chop the onions for dinner or take a shower. Your job is to care for the baby, your own health, and well-being.
Babies learn how to be alone and do their own ‘work’ by being in your presence but not interacting, and that’s an important developmental task for all babies to master. Allow baby to sit in a swing and have some time alone to visually explore their world. Always be in line of sight. Dependency is the natural state of small humans, and feeling safe is essential to early development.
But don’t worry, many babies want you to put them down well before they can crawl, so they can explore and start tearing up your house.