2 year olds do remember being yelled at.
Although the 2 year old remembering being yelled at is often not a detailed and conscious memory and instead the 2 year old stores the incident of being yelled at as a somatic body memory or an emotional, physiological reaction like an increased heart rate or feeling of insecurity that can also lead to emotional, behavioral and social patterns later in life.
Toddlers and 2 year old's often won't remember the specific words that were yelled at them, but the toddler or 2 year old will often remember the fear, the yelling and the shift in the parents or caregivers face.
And while the toddler or 2 year old might not consciously recall being yelled at such as in a booster seat, their body will retain the stress reaction of that experience.
Regular yelling at a toddler or 2 year old can cause them to feel insecure and lead to anxiety, difficulty in attachment or even learning to be unnaturally quiet to avoid punishment.
And while occasional shouting at a toddler or 2 year old won't usually cause them long term trauma, but repeated and consistent yelling can affect the toddlers or 2 year old's development.
And if you yell, it's also important to follow up with positive interactions, like with kisses, hugs and playtime to repair the secure attachment.
Toddlers can start forming lasting memories by the time they are 2 years old to 2.5 years old.
However these memories that the toddler can form are often also fragmented and disorganized memories.
While the toddler can recall specific evens for several months at age 1 to 2, the true and long term or episodic memories which are context rich and personal recollections often begin around the ages of 3 to 4 years old and are usually aided by development of language.
Most adults can recall events from as far back to as age 2.5 on average.
And memories that are made before age 2 are often lost, which is also known as childhood amnesia, if the child can't verbalize the memories at the time they occur.
A 13 month old toddler might even remember a single event that occurred for up to a week, while an 18 month old toddler might even remember 4 events that happened for a week.
Things that can factor into a toddlers memory are emotional or highly distinct events, which are often remembered better.
And long term memory capacity also increases significantly around the ages of 17 months to 24 months of age.
And for children under 4 years of age, memories usually lack full context and are also remembered as fragmented images, emotions and behaviors.
New research now also suggests that before the age of 7, you can also remember plenty from before you were age 3.
Although at around age 7, you start to forget those things and the memories will fade away from you forever.