You really want YAML::XS to behave more like YAML::Syck here? Because I think YAML::XS's behaviour is more correct than YAML::Syck's. Demonstration:

#!/usr/bin/env perl          
use strict;                  
use warnings;                
use YAML::XS ();
use YAML::Syck ();

my $data = do { local $/; <DATA> };

print "With YAML::XS...\n";
my $xs = YAML::XS::Load($data);
for my $person (@$xs) {
    print "$person->{name} is happy\n" if $person->{happy};
}

print "With YAML::Syck...\n";
my $syck = YAML::Syck::Load($data);
for my $person (@$syck) {
    print "$person->{name} is happy\n" if $person->{happy};
}

__DATA__
-
  name: Bob Johnson
  active: true
  happy: false
-
  name: Bill Johnson
  active: true
  happy: true
-
  name: Frank Johnson
  active: false
  happy: false
-
  name: George Johnson
  active: false
  happy: true
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YAML::Syck claims that Bob and Frank Johnson are happy!

It's true that the ${\$VAR1->[0]{'active'}} bits in the Data::Dumper output look funny, but that seems to be an optimization that YAML::XS is applying; using the same SV structure (if you don't know what an SV structure is, perlguts probably has more info than you want) to represent all booleans in the whole output data structure.

I can achieve a similar effect using Data::Alias (note that Data::Alias is broken in Perl 5.18):

#!/usr/bin/env perl
use strict;
use warnings;

use Data::Alias;
use Data::Dumper;

my $false = !! 0;
my $true  = !! 1;

my (@foo, @bar);
alias $foo[0] = $false;
alias $bar[0] = $false;
alias $foo[1] = $true;
alias $bar[1] = $true;

print Dumper \@foo, \@bar;
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