When do kids understand lying?

TMWarren85

My daughter is 3.5 (will be 4 in June) and has been lying a lot lately. Not about anything serious, but about things like what she ate for lunch, or if she washed her hands after she went potty. It's usually things I already know the answer to (I pack her lunch for school, and I can hear the water running), I will question her, she will tell me something (not the right answer) and I will ask her again. Sometimes I will ask if she's telling the truth, or a story, or lying (some version), or I will say I already know, or I can call Grandma and ask and she will hold out for a while. Is she too young to understand the concept of truth?

Another side- Saturday she had to wait on DH to play with her and I heard her in the hall say "I don't love daddy anymore" so I told her to come talk to us and she of course lied about it. I knew she was lying because she was scared to get in trouble that time, and tried to explain she would be in less trouble if she told me the truth. But I think that went over her head too...

Is she too young to grasp these concepts? She's such a smart kid, and she is very intuitive but I don't know at what point the intangible concepts start to make sense.