  Harris's correlation inequality states that any two monotone functions on the
Boolean hypercube are positively correlated. Talagrand \cite{Talcorr} started a
line of works in search of quantitative versions of this fact by providing a
lower bound on the correlation in terms of the influences of the functions. A
famous conjecture of Chv\'{a}tal \cite{Chvatal} was found by Friedgut, Kahn,
Kalai and Keller \cite{FKKK} to be equivalent to a certain strengthening of
Talagrand's bound, conjectured to hold true when one of the functions is
antipodal (hence $g(x) = 1-g(-x)$). Motivated by this conjecture, we strengthen
some of those bounds by giving estimates that also involve the second order
Fourier coefficients of the functions. In particular we show that in the bounds
due to Talagrand and due to Keller, Mossel and Sen \cite{KMS14}, a logarithmic
factor can be replaced by its square root when one of the functions is
antipodal. Our proofs follow a different route than the ones in the literature,
and the analysis is carried out in the Gaussian setting.
