Finding the repeatability of a behaviour

Question

I want to compute linear model based repeatability of a behaviour using intraclass correlation coefficient (the proportion of the total variance accounted for by the interindividual differences).

Equation= variance explained by individual id/ variance explained by individual id + residual variance

I made the model

j1 <- lmer(boldnessj~ assay  +
             (1|id), data=juvenile)

The output

 Groups   Name        Variance Std.Dev.
 id       (Intercept) 0.2817   0.5308  
 Residual             0.7155   0.8459  
Number of obs: 120, groups:  id, 60

Fixed effects:
            Estimate Std. Error       df t value Pr(>|t|)
(Intercept)  0.10301    0.25362 81.54591   0.406    0.686
assay       -0.05997    0.15444 59.00000  -0.388    0.699

Correlation of Fixed Effects:
      (Intr)
assay -0.913

can I use this model for finding the repeatability of specified behaviour? because p value for the assay is not significant.

is the model good for estimating repeatability