Actors who have a simian line can be expected to excell in performing 'intense' roles (find more 'famous simian line holders': HERE).
The distal phalange of his left thumb appears to be relatively long (which is associated with a strong impulse to 'will').
The fingers of his left hand are 'balanced' and his left palm is 'square shaped'. Robert De Niro's personality has often been described as an 'introverted-person'; he is e.g. known for avoiding personal interviews.
Robert De Niro appears to have a Sydney line (= extended head line) in his right hand.
The distal phalange of his right thumb appears to be relatively long (which is associated with a strong impulse to 'will').
The fingers of his right hand are characterized by a long pinky finger + a relatively long ring finger resulting in (but his 2D:4D digit ratio looks normal (= pointer finger is slightly shorter than the long ring finger).
Robert De Niro's world fame can be attributed to the diversity of his acting skills as seen in various movies like e.g.: 'The Godfather - part II' (1974), 'Taxi Driver' (1974), 'The Deer Hunter' (1980), 'Raging Bull' (1981), 'Awakenings' (1991), and 'The Good Shepherd' (2007).
Take a look at 8 photos of: 'ROBERT DE NIRO'S HANDS'
Or, take a look at ...:
"The Godfather - part II" (official trailer)
"The Godfather - part II" (1974) received 6 acedemy awards, including: "... Best supporting actor: Robert De Niro..."
"Taxi Driver" (official trailer)
In "Taxi Driver" (1974) Robert De Niro won the 'best actor' award from the 'Los Angeles Film Critics Associations' (+ an Academy Award nomination for 'best actor').
"... De Niro, he banged the drum slowly; the critics called him a brilliant new talent, and under mean streams they said he was a genius..."
"Awakenings" (official trailer)
In "Awakenings" (1991) Robert De Niro won the 'best actor' award from the 'National Board Review' (+ an Academy Award nomination for 'best actor').