Educational scientist and expert on crying and sleep problems in babies
Of course you have to protect your newborn baby. An infant can not even guess that it can really hurt his little sibling. Jealousy can lead to violent aggressive reactions in individual cases.
However, you should certainly ignore a little overly caressing your toddler, as long as your baby is not harmed. If you always complain to your toddler as soon as it approaches the baby, it can increase his jealousy and strain the relationship. So it is best to be alert, but not too anxious when you first get in touch with them.
But it makes sense to always be close to the two, in case the baby should be overburdened. Even with three- and four-year-old children, it can happen that the curiosity and adventurousness are too big. Your brain development is not yet so far that they always act reasonable and considerate. This is not meant to be evil at all, but simply a consequence of brain development, which is far from complete.
After the first few weeks, you can assess your toddler a little better and depending on your experience, it may then be possible to leave the room for a short time - but within earshot and only for a short time! Encourage your toddler to come with you and help you.
They do not imply that your toddler is malignant, but only protect him from the consequences of his curiosity. Alone and unobserved with a new, small being, it simply can not control enough.
Avoiding situations where your children are unobserved simply makes you feel better because you feel safer. And if you plan a fixed time each day while giving your undivided attention to your toddler, it does not feel reset but acknowledged and respected. That also helps against jealousy.
If another baby comes