Studies reveal that age more difficult during the growth and development of children are three years old. It is known as the phase of negativism. The attitude of the child is often of continued denial.
Around the age of two and up to four approximately, the children live a common stage of denial. Your goal is not to inconvenience parents, but to find its own identity. From this age, you begin to experience the autonomy and ability of movement that may have by themselves and in this way it increases the perception that they have towards the world around them.
What to do?
be tolerant of their behaviors. At this age they are forming their personality and it is a mistake not to let them know its essence. This crisis will not be permanent, but it is necessary to know how to deal with it, setting clear limits to their desires to prevail that contribute to form a good concept of your own individuality. This will allow your development to be positive.
The problem is not the mother nor the family, nor their environment. At this stage they want to do what they want, while you say NO! it is when you're going to do because they want to gain autonomy and become independent people. Parents and family members should maintain a firm position, reasonable, and logical.