1 human nature

2 humanity

3 human

4 the totality of human attributes

1 willful

2 headstrong

3 unruly

1 individuality

2 personality

1 tell-tale

2 informer (esp. to police)

3 whistleblower

4 grass

1 woman

2 the female sex

1 to cultivate the heart and nurture the character (idiom); to improve oneself by meditation

1 the palest ink is better than the best memory (idiom)

1 inextricably linked (idiom)

2 inseparable

1 It is hard to change one's essential nature (idiom). You can't change who you are.

2 Can the leopard change his spots? (Jeremiah 13:23)

1 it is easier to change mountains and rivers than to alter one's character (idiom)

2 you can't change who you are

3 Can the leopard change his spots?