Baby hasn't downloaded the language and courtesy pack yet, but it will come!
Can a baby of a few months throw tantrums?
It's important to remember that your newborn or baby of a few months doesn't yet have the brain capacity to manipulate or throw the famous tantrums.
The process of manipulation, tantrums, bargaining requires having already acquired language. Moreover, it requires cognitive activity much more advanced than that of the newborn and baby generally of babywearing age (newborn = no verbal language).
However, know for later that these stages of negotiation, manipulation (whatever you call them) are part of the different stages of communication learning in young children. Note that we're talking here about young children and not babies of babywearing age.
Sometimes what we mistake for a tantrum is actually a simple nonverbal reaction from baby, who for now can only communicate through clumsy gestures, crying and grunting, admittedly cute at times but frankly exhausting in a waiting line.
It's not against you, nor premeditated to test your parental authority (as might be the case for a 4-year-old child). If they cry, it's because they're communicating a need or a reaction to the context (hot, cold, hungry, discovering an object...). These are sometimes frustrating stages for both child and adult.
We can hear these phrases "Let them cry, they're testing you, they're being fussy...". But if it's a young baby, you now know that's not the case. They're communicating a need with their limited means. A need for attention, food, warmth... it's up to you to discover which one to respond to!
At what age does a child/baby throw tantrums?
It's difficult to give a precise age for when your child acquires the ability to throw tantrums, but the literature on the subject often agrees on 18 months - 2 years.
Your child must first be able to desire something and express it. At this age, they may start testing their own limits and those of their loved ones (you, therefore). Bear in mind once again that your child doesn't premeditate their meltdowns to irritate you, but rather to discover and therefore understand the framework and boundaries. To learn limits, they must actually cross them to experience them. During this time, you as the parent embody the boundary that your child will come into contact with. And yes, it's a sometimes irritating moment if we forget that it's actually a learning process.
To distinguish between want/"tantrum" and need, you can therefore if possible try to understand what your child is feeling or seeking. It can be difficult to know whether it's a request motivated by desire or a need. In most cases, it's the adult (especially if they're not very available or focused) who perceives a child's need for communication as a tantrum. We see the tip of the iceberg as the tantrum without seeing the need underneath (need to eat, for attention, to play...).
In short, as far as we're concerned here with babywearing and babies, we won't really have to deal with tantrums.